Add support for logging the current role

*** a/doc/src/sgml/config.sgml
--- b/doc/src/sgml/config.sgml
***************
*** 3504,3510 **** local0.*    /var/log/postgresql
              </row>
              <row>
               <entry><literal>%u</literal></entry>
!              <entry>User name</entry>
               <entry>yes</entry>
              </row>
              <row>
--- 3504,3515 ----
              </row>
              <row>
               <entry><literal>%u</literal></entry>
!              <entry>User name which was used to authenticate to <productname>PostgreSQL</productname> with</entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>%U</literal></entry>
!              <entry>Current role name, set via <command>SET ROLE</>, the current role identifier is relevant for permission checking</entry>
               <entry>yes</entry>
              </row>
              <row>
*** a/src/backend/utils/error/elog.c
--- b/src/backend/utils/error/elog.c
***************
*** 1826,1831 **** log_line_prefix(StringInfo buf, ErrorData *edata)
--- 1826,1841 ----
  					appendStringInfoString(buf, username);
  				}
  				break;
+ 			case 'U':
+ 				if (MyProcPort)
+ 				{
+ 					const char *rolename = GetUserNameFromId(GetUserId());
+ 
+ 					if (rolename == NULL || *rolename == '\0')
+ 						rolename = _("[unknown]");
+ 					appendStringInfoString(buf, rolename);
+ 				}
+ 				break;
  			case 'd':
  				if (MyProcPort)
  				{

*** a/doc/src/sgml/config.sgml
--- b/doc/src/sgml/config.sgml
***************
*** 3504,3510 **** local0.*    /var/log/postgresql
              </row>
              <row>
               <entry><literal>%u</literal></entry>
!              <entry>User name</entry>
               <entry>yes</entry>
              </row>
              <row>
--- 3504,3515 ----
              </row>
              <row>
               <entry><literal>%u</literal></entry>
!              <entry>User name which was used to authenticate to <productname>PostgreSQL</productname> with</entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>%R</literal></entry>
!              <entry>Current role name, set via <command>SET ROLE</>, the current role identifier is relevant for permission checking</entry>
               <entry>yes</entry>
              </row>
              <row>
*** a/src/backend/utils/error/elog.c
--- b/src/backend/utils/error/elog.c
***************
*** 1826,1831 **** log_line_prefix(StringInfo buf, ErrorData *edata)
--- 1826,1841 ----
  					appendStringInfoString(buf, username);
  				}
  				break;
+ 			case 'R':
+ 				if (MyProcPort)
+ 				{
+ 					const char *rolename = GetUserNameFromId(GetUserId());
+ 
+ 					if (rolename == NULL || *rolename == '\0')
+ 						rolename = _("[unknown]");
+ 					appendStringInfoString(buf, rolename);
+ 				}
+ 				break;
  			case 'd':
  				if (MyProcPort)
  				{

*** a/src/backend/utils/error/elog.c
--- b/src/backend/utils/error/elog.c
***************
*** 3,8 ****
--- 3,17 ----
   * elog.c
   *	  error logging and reporting
   *
+  * A few comments about situations where error processing is called:
+  *
+  * We need to be cautious of both a performance hit when logging, since
+  * log messages can be generated at a huge rate if every command is being
+  * logged and we also need to watch out for what can happen when we are
+  * trying to log from an aborted transaction.  Specifically, attempting to
+  * do SysCache lookups and possibly use other usually available backend
+  * systems will fail badly when logging from an aborted transaction.
+  *
   * Some notes about recursion and errors during error processing:
   *
   * We need to be robust about recursive-error scenarios --- for example,

*** a/doc/src/sgml/config.sgml
--- b/doc/src/sgml/config.sgml
***************
*** 3504,3510 **** local0.*    /var/log/postgresql
              </row>
              <row>
               <entry><literal>%u</literal></entry>
!              <entry>User name</entry>
               <entry>yes</entry>
              </row>
              <row>
--- 3504,3517 ----
              </row>
              <row>
               <entry><literal>%u</literal></entry>
!              <entry>User name which was used to authenticate to <productname>PostgreSQL</productname> with</entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>%o</literal></entry>
!              <entry>Current role OID, set via <command>SET ROLE</>, the
! 			 current role is relevant for permission checking, the mapping
! 			 from OID to role can be found in the pg_authid catalog</entry>
               <entry>yes</entry>
              </row>
              <row>
*** a/src/backend/utils/error/elog.c
--- b/src/backend/utils/error/elog.c
***************
*** 3,8 ****
--- 3,17 ----
   * elog.c
   *	  error logging and reporting
   *
+  * A few comments about situations where error processing is called:
+  *
+  * We need to be cautious of both a performance hit when logging, since
+  * log messages can be generated at a huge rate if every command is being
+  * logged and we also need to watch out for what can happen when we are
+  * trying to log from an aborted transaction.  Specifically, attempting to
+  * do SysCache lookups and possibly use other usually available backend
+  * systems will fail badly when logging from an aborted transaction.
+  *
   * Some notes about recursion and errors during error processing:
   *
   * We need to be robust about recursive-error scenarios --- for example,
***************
*** 1826,1831 **** log_line_prefix(StringInfo buf, ErrorData *edata)
--- 1835,1852 ----
  					appendStringInfoString(buf, username);
  				}
  				break;
+ 			case 'o':
+ 				{
+ 					Oid curr_role;
+ 					int curr_sec_context;
+ 
+ 					GetUserIdAndSecContext(&curr_role,&curr_sec_context);
+ 					if (OidIsValid(curr_role))
+ 						appendStringInfo(buf, "%u", curr_role);
+ 					else
+ 						appendStringInfoString(buf, _("[unknown]"));
+ 				}
+ 				break;
  			case 'd':
  				if (MyProcPort)
  				{

*** a/doc/src/sgml/config.sgml
--- b/doc/src/sgml/config.sgml
***************
*** 3504,3510 **** local0.*    /var/log/postgresql
              </row>
              <row>
               <entry><literal>%u</literal></entry>
!              <entry>User name</entry>
               <entry>yes</entry>
              </row>
              <row>
--- 3504,3523 ----
              </row>
              <row>
               <entry><literal>%u</literal></entry>
!              <entry>Session user name, typically the user name which was used
!              to authenticate to <productname>PostgreSQL</productname> with,
!              but can be changed by a superuser, see <command>SET SESSION
!              AUTHORIZATION</></entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>%U</literal></entry>
!              <entry>Current role name, when set with <command>SET ROLE</>;
!              the current role identifier is relevant for permission checking;
!              Returns 'none' if the current role matches the session user.
!              Note: Log messages from inside <literal>SECURITY DEFINER</>
!              functions will show the calling role, not the effective role
!              inside the <literal>SECURITY DEFINER</> function</entry>
               <entry>yes</entry>
              </row>
              <row>
***************
*** 3731,3737 **** FROM pg_stat_activity;
          (<acronym>CSV</>) format,
          with these columns:
          timestamp with milliseconds,
!         user name,
          database name,
          process ID,
          client host:port number,
--- 3744,3751 ----
          (<acronym>CSV</>) format,
          with these columns:
          timestamp with milliseconds,
!         session user name,
!         current role name,
          database name,
          process ID,
          client host:port number,
***************
*** 3755,3760 **** FROM pg_stat_activity;
--- 3769,3778 ----
          location of the error in the PostgreSQL source code
          (if <varname>log_error_verbosity</> is set to <literal>verbose</>),
          and application name.
+ 
+         For additional details on the definition of the above columns, refer
+         to the documentation for log_line_prefix.
+ 
          Here is a sample table definition for storing CSV-format log output:
  
  <programlisting>
***************
*** 3762,3767 **** CREATE TABLE postgres_log
--- 3780,3786 ----
  (
    log_time timestamp(3) with time zone,
    user_name text,
+   role_name text,
    database_name text,
    process_id integer,
    connection_from text,
*** a/src/backend/commands/variable.c
--- b/src/backend/commands/variable.c
***************
*** 760,765 **** assign_session_authorization(const char *value, bool doit, GucSource source)
--- 760,770 ----
  	return result;
  }
  
+ /*
+  * function to return the stored session username, needed because we
+  * can't do catalog lookups when possibly being called after an error,
+  * eg: from elog.c or part of GUC handling.
+  */
  const char *
  show_session_authorization(void)
  {
***************
*** 885,890 **** assign_role(const char *value, bool doit, GucSource source)
--- 890,900 ----
  	return result;
  }
  
+ /*
+  * function to return the stored role username, needed because we
+  * can't do catalog lookups when possibly being called after an error,
+  * eg: from elog.c or part of GUC handling.
+  */
  const char *
  show_role(void)
  {
*** a/src/backend/utils/error/elog.c
--- b/src/backend/utils/error/elog.c
***************
*** 3,8 ****
--- 3,17 ----
   * elog.c
   *	  error logging and reporting
   *
+  * A few comments about situations where error processing is called:
+  *
+  * We need to be cautious of both a performance hit when logging, since
+  * log messages can be generated at a huge rate if every command is being
+  * logged and we also need to watch out for what can happen when we are
+  * trying to log from an aborted transaction.  Specifically, attempting to
+  * do SysCache lookups and possibly use other usually available backend
+  * systems will fail badly when logging from an aborted transaction.
+  *
   * Some notes about recursion and errors during error processing:
   *
   * We need to be robust about recursive-error scenarios --- for example,
***************
*** 59,64 ****
--- 68,74 ----
  
  #include "access/transam.h"
  #include "access/xact.h"
+ #include "commands/variable.h"
  #include "libpq/libpq.h"
  #include "libpq/pqformat.h"
  #include "mb/pg_wchar.h"
***************
*** 1817,1831 **** log_line_prefix(StringInfo buf, ErrorData *edata)
  				}
  				break;
  			case 'u':
- 				if (MyProcPort)
  				{
! 					const char *username = MyProcPort->user_name;
! 
! 					if (username == NULL || *username == '\0')
! 						username = _("[unknown]");
! 					appendStringInfoString(buf, username);
  				}
  				break;
  			case 'd':
  				if (MyProcPort)
  				{
--- 1827,1850 ----
  				}
  				break;
  			case 'u':
  				{
! 				const char *session_auth = show_session_authorization();
! 				if (*session_auth != '\0')
! 					appendStringInfoString(buf, session_auth);
! 				else
! 					if (MyProcPort)
! 					{
! 						const char *username = MyProcPort->user_name;
! 
! 						if (username == NULL || *username == '\0')
! 							username = _("[unknown]");
! 						appendStringInfoString(buf, username);
! 					}
  				}
  				break;
+ 			case 'U':
+ 				appendStringInfoString(buf, show_role());
+ 				break;
  			case 'd':
  				if (MyProcPort)
  				{
***************
*** 1952,1957 **** appendCSVLiteral(StringInfo buf, const char *data)
--- 1971,1978 ----
  static void
  write_csvlog(ErrorData *edata)
  {
+ 	const char *session_auth = show_session_authorization();
+ 
  	StringInfoData buf;
  	bool		print_stmt = false;
  
***************
*** 1989,1997 **** write_csvlog(ErrorData *edata)
  	appendStringInfoString(&buf, formatted_log_time);
  	appendStringInfoChar(&buf, ',');
  
! 	/* username */
! 	if (MyProcPort)
! 		appendCSVLiteral(&buf, MyProcPort->user_name);
  	appendStringInfoChar(&buf, ',');
  
  	/* database name */
--- 2010,2031 ----
  	appendStringInfoString(&buf, formatted_log_time);
  	appendStringInfoChar(&buf, ',');
  
! 	/* session username, as done for %u */
! 	if (*session_auth != '\0')
! 		appendCSVLiteral(&buf, session_auth);
! 	else
! 		if (MyProcPort)
! 		{
! 			const char *username = MyProcPort->user_name;
! 
! 			if (username == NULL || *username == '\0')
! 				username = _("[unknown]");
! 			appendCSVLiteral(&buf, username);
! 		}
! 	appendStringInfoChar(&buf, ',');
! 
! 	/* current role, same as %U */
! 	appendCSVLiteral(&buf, show_role());
  	appendStringInfoChar(&buf, ',');
  
  	/* database name */

*** a/doc/src/sgml/config.sgml
--- b/doc/src/sgml/config.sgml
***************
*** 3504,3510 **** local0.*    /var/log/postgresql
              </row>
              <row>
               <entry><literal>%u</literal></entry>
!              <entry>User name</entry>
               <entry>yes</entry>
              </row>
              <row>
--- 3504,3523 ----
              </row>
              <row>
               <entry><literal>%u</literal></entry>
!              <entry>Session user name, typically the user name which was used
!              to authenticate to <productname>PostgreSQL</productname> with,
!              but can be changed by a superuser, see <command>SET SESSION
!              AUTHORIZATION</></entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>%U</literal></entry>
!              <entry>Current role name, when set with <command>SET ROLE</>;
!              the current role identifier is relevant for permission checking;
!              Returns 'none' if the current role matches the session user.
!              Note: Log messages from inside <literal>SECURITY DEFINER</>
!              functions will show the calling role, not the effective role
!              inside the <literal>SECURITY DEFINER</> function</entry>
               <entry>yes</entry>
              </row>
              <row>
***************
*** 3621,3626 **** FROM pg_stat_activity;
--- 3634,3662 ----
        </listitem>
       </varlistentry>
  
+      <varlistentry id="guc-log-csv-fields" xreflabel="log_csv_fields">
+       <term><varname>log_csv_fields</varname> (<type>string</type>)</term>
+       <indexterm>
+        <primary><varname>log_csv_fields</> configuration parameter</primary>
+       </indexterm>
+       <listitem>
+        <para>
+         Controls the set and order of the fields which are written out in
+         the CSV-format log file.
+ 
+         The default is: log_time, user_name, database_name, process_id,
+         connection_from, session_id, session_line_num, command_tag,
+         session_start_time, virtual_transaction_id, transaction_id,
+         error_severity, sql_state_code, message, detail, hint,
+         internal_query, internal_query_pos, context, query, query_pos,
+         location, application_name
+ 
+         For details on what these fields are, refer to the log_line_prefix
+         and CSV logging documentation.
+        </para>
+       </listitem>
+      </varlistentry>
+ 
       <varlistentry id="guc-log-lock-waits" xreflabel="log_lock_waits">
        <term><varname>log_lock_waits</varname> (<type>boolean</type>)</term>
        <indexterm>
***************
*** 3728,3761 **** FROM pg_stat_activity;
          Including <literal>csvlog</> in the <varname>log_destination</> list
          provides a convenient way to import log files into a database table.
          This option emits log lines in comma-separated-values
!         (<acronym>CSV</>) format,
!         with these columns:
!         timestamp with milliseconds,
!         user name,
!         database name,
!         process ID,
!         client host:port number,
!         session ID,
!         per-session line number,
!         command tag,
!         session start time,
!         virtual transaction ID,
!         regular transaction ID,
!         error severity,
!         SQLSTATE code,
!         error message,
!         error message detail,
!         hint,
!         internal query that led to the error (if any),
!         character count of the error position therein,
!         error context,
!         user query that led to the error (if any and enabled by
!         <varname>log_min_error_statement</>),
!         character count of the error position therein,
!         location of the error in the PostgreSQL source code
          (if <varname>log_error_verbosity</> is set to <literal>verbose</>),
!         and application name.
!         Here is a sample table definition for storing CSV-format log output:
  
  <programlisting>
  CREATE TABLE postgres_log
--- 3764,3833 ----
          Including <literal>csvlog</> in the <varname>log_destination</> list
          provides a convenient way to import log files into a database table.
          This option emits log lines in comma-separated-values
!         (<acronym>CSV</>) format.  These columns may be included in the CSV
!         output:
!         log_time,                   # timestamp with milliseconds
!         user_name,                  # session user name
!         role_name,                  # current role name
!         database_name,              # database name
!         process_id,                 # process ID
!         connection_from,            # client host:port number
!         session_id,                 # session ID
!         session_line_number,        # per-session line number
!         command_tag,                # command tag
!         session_start_time,         # session start time
!         virtual_transaction_id,     # virtual transaction ID
!         transaction_id,             # regular transaction ID
!         error_severity,             # error severity
!         sql_state_code,             # SQLSTATE code
!         message,                    # error message
!         detail,                     # error message detail
!         hint,                       # hint
!         internal_query,             # internal query that led to the error (if any)
!         internal_query_pos,         # character count of the error position therein
!         context,                    # error context
!         query,             # user query that led to the error (if any and enabled by
!         <varname>log_min_error_statement</>)
!         query_pos,         # character count of the error position therein
!         location,          # location of the error in the PostgreSQL source code
          (if <varname>log_error_verbosity</> is set to <literal>verbose</>),
!         application_name            # application name
! 
!         The default set of columns does not include current role name, and
!         is currently:
! 
!         log_time,
!         user_name,
!         database_name,
!         process_id,
!         connection_from,
!         session_id,
!         session_line_num,
!         command_tag,
!         session_start_time,
!         virtual_transaction_id,
!         transaction_id,
!         error_severity,
!         sql_state_code,
!         message,
!         detail,
!         hint,
!         internal_query,
!         internal_query_pos,
!         context,
!         query,
!         query_pos,
!         location,
!         application_name
! 
!         The set of columns to be included, and their order, in the CSV
!         output can be controlled using the <varname>log_csv_fields</> option.
! 
!         For additional details on the definition of the above columns, refer
!         to the documentation for <varname>log_line_prefix</>.
! 
!         Here is a sample table definition for storing the default CSV-format
!         log output:
  
  <programlisting>
  CREATE TABLE postgres_log
*** a/src/backend/commands/variable.c
--- b/src/backend/commands/variable.c
***************
*** 760,765 **** assign_session_authorization(const char *value, bool doit, GucSource source)
--- 760,770 ----
  	return result;
  }
  
+ /*
+  * function to return the stored session username, needed because we
+  * can't do catalog lookups when possibly being called after an error,
+  * eg: from elog.c or part of GUC handling.
+  */
  const char *
  show_session_authorization(void)
  {
***************
*** 885,890 **** assign_role(const char *value, bool doit, GucSource source)
--- 890,900 ----
  	return result;
  }
  
+ /*
+  * function to return the stored role username, needed because we
+  * can't do catalog lookups when possibly being called after an error,
+  * eg: from elog.c or part of GUC handling.
+  */
  const char *
  show_role(void)
  {
*** a/src/backend/utils/error/elog.c
--- b/src/backend/utils/error/elog.c
***************
*** 3,8 ****
--- 3,17 ----
   * elog.c
   *	  error logging and reporting
   *
+  * A few comments about situations where error processing is called:
+  *
+  * We need to be cautious of both a performance hit when logging, since
+  * log messages can be generated at a huge rate if every command is being
+  * logged and we also need to watch out for what can happen when we are
+  * trying to log from an aborted transaction.  Specifically, attempting to
+  * do SysCache lookups and possibly use other usually available backend
+  * systems will fail badly when logging from an aborted transaction.
+  *
   * Some notes about recursion and errors during error processing:
   *
   * We need to be robust about recursive-error scenarios --- for example,
***************
*** 59,73 ****
--- 68,85 ----
  
  #include "access/transam.h"
  #include "access/xact.h"
+ #include "commands/variable.h"
  #include "libpq/libpq.h"
  #include "libpq/pqformat.h"
  #include "mb/pg_wchar.h"
  #include "miscadmin.h"
+ #include "nodes/pg_list.h"
  #include "postmaster/postmaster.h"
  #include "postmaster/syslogger.h"
  #include "storage/ipc.h"
  #include "storage/proc.h"
  #include "tcop/tcopprot.h"
+ #include "utils/builtins.h"
  #include "utils/guc.h"
  #include "utils/memutils.h"
  #include "utils/ps_status.h"
***************
*** 93,98 **** extern bool redirection_done;
--- 105,119 ----
  int			Log_error_verbosity = PGERROR_VERBOSE;
  char	   *Log_line_prefix = NULL;		/* format for extra log line info */
  int			Log_destination = LOG_DESTINATION_STDERR;
+ char	   *Log_csv_fields = NULL;
+ 
+ /* Process updates to GUC Log_csv_fields */
+ const char *
+ assign_log_csv_fields(const char *newval, bool doit, GucSource source);
+ 
+ void build_default_csvlog_list(void);
+ 
+ static List *csv_log_fields = NIL;
  
  #ifdef HAVE_SYSLOG
  
***************
*** 1817,1831 **** log_line_prefix(StringInfo buf, ErrorData *edata)
  				}
  				break;
  			case 'u':
- 				if (MyProcPort)
  				{
! 					const char *username = MyProcPort->user_name;
! 
! 					if (username == NULL || *username == '\0')
! 						username = _("[unknown]");
! 					appendStringInfoString(buf, username);
  				}
  				break;
  			case 'd':
  				if (MyProcPort)
  				{
--- 1838,1861 ----
  				}
  				break;
  			case 'u':
  				{
! 				const char *session_auth = show_session_authorization();
! 				if (*session_auth != '\0')
! 					appendStringInfoString(buf, session_auth);
! 				else
! 					if (MyProcPort)
! 					{
! 						const char *username = MyProcPort->user_name;
! 
! 						if (username == NULL || *username == '\0')
! 							username = _("[unknown]");
! 						appendStringInfoString(buf, username);
! 					}
  				}
  				break;
+ 			case 'U':
+ 				appendStringInfoString(buf, show_role());
+ 				break;
  			case 'd':
  				if (MyProcPort)
  				{
***************
*** 1921,1926 **** log_line_prefix(StringInfo buf, ErrorData *edata)
--- 1951,2114 ----
  }
  
  /*
+  * Build up the default set of CSV fields to output, in case we need it before
+  * GUC processing is done.
+  *
+  * This is more of a 'safety valve' than anything else,
+  * since GUC processing really should happen before we do any error logging.
+  * We might even want to change this eventually to just not log CSV format logs
+  * if this ever happens, to avoid a discrepency in the CSV log file which would
+  * make it difficult to load into PG.
+  */
+ void
+ build_default_csvlog_list(void)
+ {
+ 	List		*new_csv_fields = NIL;
+ 	MemoryContext oldcontext;
+ 
+ 	oldcontext = MemoryContextSwitchTo(TopMemoryContext);
+ 
+ 	new_csv_fields = lappend_int(new_csv_fields,CSVLOG_LOG_TIME);
+ 	new_csv_fields = lappend_int(new_csv_fields,CSVLOG_USER_NAME);
+ 	new_csv_fields = lappend_int(new_csv_fields,CSVLOG_DATABASE_NAME);
+ 	new_csv_fields = lappend_int(new_csv_fields,CSVLOG_PROCESS_ID);
+ 	new_csv_fields = lappend_int(new_csv_fields,CSVLOG_CONNECTION_FROM);
+ 	new_csv_fields = lappend_int(new_csv_fields,CSVLOG_SESSION_ID);
+ 	new_csv_fields = lappend_int(new_csv_fields,CSVLOG_SESSION_LINE_NUM);
+ 	new_csv_fields = lappend_int(new_csv_fields,CSVLOG_COMMAND_TAG);
+ 	new_csv_fields = lappend_int(new_csv_fields,CSVLOG_SESSION_START_TIME);
+ 	new_csv_fields = lappend_int(new_csv_fields,CSVLOG_VIRTUAL_TRANSACTION_ID);
+ 	new_csv_fields = lappend_int(new_csv_fields,CSVLOG_TRANSACTION_ID);
+ 	new_csv_fields = lappend_int(new_csv_fields,CSVLOG_ERROR_SEVERITY);
+ 	new_csv_fields = lappend_int(new_csv_fields,CSVLOG_SQL_STATE_CODE);
+ 	new_csv_fields = lappend_int(new_csv_fields,CSVLOG_MESSAGE);
+ 	new_csv_fields = lappend_int(new_csv_fields,CSVLOG_DETAIL);
+ 	new_csv_fields = lappend_int(new_csv_fields,CSVLOG_HINT);
+ 	new_csv_fields = lappend_int(new_csv_fields,CSVLOG_INTERNAL_QUERY);
+ 	new_csv_fields = lappend_int(new_csv_fields,CSVLOG_INTERNAL_QUERY_POS);
+ 	new_csv_fields = lappend_int(new_csv_fields,CSVLOG_CONTEXT);
+ 	new_csv_fields = lappend_int(new_csv_fields,CSVLOG_QUERY);
+ 	new_csv_fields = lappend_int(new_csv_fields,CSVLOG_QUERY_POS);
+ 	new_csv_fields = lappend_int(new_csv_fields,CSVLOG_LOCATION);
+ 	new_csv_fields = lappend_int(new_csv_fields,CSVLOG_APPLICATION_NAME);
+ 
+ 	/* put new list in place */
+ 	csv_log_fields = new_csv_fields;
+ 
+ 	MemoryContextSwitchTo(oldcontext);
+ 
+ 	return;
+ }
+ 
+ 
+ /*
+  * Process the list of fields to be sent to the CSV log file
+  */
+ const char *
+ assign_log_csv_fields(const char *newval, bool doit, GucSource source)
+ {
+ 	/* Verify the list is valid */
+ 	List		*new_csv_fields = NIL;
+ 	List		*column_list = NIL;
+ 	ListCell	*l;
+ 	char		*rawstring;
+ 	MemoryContext oldcontext;
+ 
+ 	/*
+ 	 * We need the allocations done for the csv_log_fields list to
+ 	 * be preserved, so allocate them in TopMemoryContext.
+ 	 */
+ 	oldcontext = MemoryContextSwitchTo(TopMemoryContext);
+ 
+ 	/* Need a modifyable version to pass to SplitIdentifierString */
+ 	rawstring = pstrdup(newval);
+ 
+     /* Parse string into list of identifiers */
+     if (!SplitIdentifierString(rawstring, ',', &column_list))
+ 	{
+ 		list_free(column_list);
+ 		return NULL;
+ 	}
+ 
+ 	/*
+ 	 * Loop through all of the fields provided by the user and build
+ 	 * up our new_csv_fields list which will be processed by write_csvlog
+ 	 */
+ 	foreach(l, column_list)
+ 	{
+ 		if (pg_strcasecmp(lfirst(l),"log_time") == 0)
+ 			new_csv_fields = lappend_int(new_csv_fields,CSVLOG_LOG_TIME);
+ 		else if (pg_strcasecmp(lfirst(l),"user_name") == 0)
+ 			new_csv_fields = lappend_int(new_csv_fields,CSVLOG_USER_NAME);
+ 		else if (pg_strcasecmp(lfirst(l),"role_name") == 0)
+ 			new_csv_fields = lappend_int(new_csv_fields,CSVLOG_ROLE_NAME);
+ 		else if (pg_strcasecmp(lfirst(l),"database_name") == 0)
+ 			new_csv_fields = lappend_int(new_csv_fields,CSVLOG_DATABASE_NAME);
+ 		else if (pg_strcasecmp(lfirst(l),"process_id") == 0)
+ 			new_csv_fields = lappend_int(new_csv_fields,CSVLOG_PROCESS_ID);
+ 		else if (pg_strcasecmp(lfirst(l),"connection_from") == 0)
+ 			new_csv_fields = lappend_int(new_csv_fields,CSVLOG_CONNECTION_FROM);
+ 		else if (pg_strcasecmp(lfirst(l),"session_id") == 0)
+ 			new_csv_fields = lappend_int(new_csv_fields,CSVLOG_SESSION_ID);
+ 		else if (pg_strcasecmp(lfirst(l),"session_line_num") == 0)
+ 			new_csv_fields = lappend_int(new_csv_fields,CSVLOG_SESSION_LINE_NUM);
+ 		else if (pg_strcasecmp(lfirst(l),"command_tag") == 0)
+ 			new_csv_fields = lappend_int(new_csv_fields,CSVLOG_COMMAND_TAG);
+ 		else if (pg_strcasecmp(lfirst(l),"session_start_time") == 0)
+ 			new_csv_fields = lappend_int(new_csv_fields,CSVLOG_SESSION_START_TIME);
+ 		else if (pg_strcasecmp(lfirst(l),"virtual_transaction_id") == 0)
+ 			new_csv_fields = lappend_int(new_csv_fields,CSVLOG_VIRTUAL_TRANSACTION_ID);
+ 		else if (pg_strcasecmp(lfirst(l),"transaction_id") == 0)
+ 			new_csv_fields = lappend_int(new_csv_fields,CSVLOG_TRANSACTION_ID);
+ 		else if (pg_strcasecmp(lfirst(l),"error_severity") == 0)
+ 			new_csv_fields = lappend_int(new_csv_fields,CSVLOG_ERROR_SEVERITY);
+ 		else if (pg_strcasecmp(lfirst(l),"sql_state_code") == 0)
+ 			new_csv_fields = lappend_int(new_csv_fields,CSVLOG_SQL_STATE_CODE);
+ 		else if (pg_strcasecmp(lfirst(l),"message") == 0)
+ 			new_csv_fields = lappend_int(new_csv_fields,CSVLOG_MESSAGE);
+ 		else if (pg_strcasecmp(lfirst(l),"detail") == 0)
+ 			new_csv_fields = lappend_int(new_csv_fields,CSVLOG_DETAIL);
+ 		else if (pg_strcasecmp(lfirst(l),"hint") == 0)
+ 			new_csv_fields = lappend_int(new_csv_fields,CSVLOG_HINT);
+ 		else if (pg_strcasecmp(lfirst(l),"internal_query") == 0)
+ 			new_csv_fields = lappend_int(new_csv_fields,CSVLOG_INTERNAL_QUERY);
+ 		else if (pg_strcasecmp(lfirst(l),"internal_query_pos") == 0)
+ 			new_csv_fields = lappend_int(new_csv_fields,CSVLOG_INTERNAL_QUERY_POS);
+ 		else if (pg_strcasecmp(lfirst(l),"context") == 0)
+ 			new_csv_fields = lappend_int(new_csv_fields,CSVLOG_CONTEXT);
+ 		else if (pg_strcasecmp(lfirst(l),"query") == 0)
+ 			new_csv_fields = lappend_int(new_csv_fields,CSVLOG_QUERY);
+ 		else if (pg_strcasecmp(lfirst(l),"query_pos") == 0)
+ 			new_csv_fields = lappend_int(new_csv_fields,CSVLOG_QUERY_POS);
+ 		else if (pg_strcasecmp(lfirst(l),"location") == 0)
+ 			new_csv_fields = lappend_int(new_csv_fields,CSVLOG_LOCATION);
+ 		else if (pg_strcasecmp(lfirst(l),"application_name") == 0)
+ 			new_csv_fields = lappend_int(new_csv_fields,CSVLOG_APPLICATION_NAME);
+ 		else
+ 		{
+ 			/* handle error, might need to do better than this */
+ 			return NULL;
+ 		}
+ 	}
+ 
+ 	if (doit)
+ 	{
+ 		/* put new list in place */
+ 		List *old_list = csv_log_fields;
+ 
+ 		csv_log_fields = new_csv_fields;
+ 
+ 		if (old_list != NIL)
+ 			list_free(old_list);
+ 	}
+ 
+ 	/* Switch back to the calling context */
+ 	MemoryContextSwitchTo(oldcontext);
+ 
+ 	return newval;
+ }
+ 
+ /*
   * append a CSV'd version of a string to a StringInfo
   * We use the PostgreSQL defaults for CSV, i.e. quote = escape = '"'
   * If it's NULL, append nothing.
***************
*** 1946,1953 **** appendCSVLiteral(StringInfo buf, const char *data)
  }
  
  /*
!  * Constructs the error message, depending on the Errordata it gets, in a CSV
!  * format which is described in doc/src/sgml/config.sgml.
   */
  static void
  write_csvlog(ErrorData *edata)
--- 2134,2141 ----
  }
  
  /*
!  * Constructs the error message, depending on the Errordata it gets, in the CSV
!  * format requested by the user, based on the log_csv_fields GUC.
   */
  static void
  write_csvlog(ErrorData *edata)
***************
*** 1961,1966 **** write_csvlog(ErrorData *edata)
--- 2149,2158 ----
  	/* has counter been reset in current process? */
  	static int	log_my_pid = 0;
  
+ 	ListCell	*l;
+ 
+ 	const char *session_auth = show_session_authorization();
+ 
  	/*
  	 * This is one of the few places where we'd rather not inherit a static
  	 * variable's value from the postmaster.  But since we will, reset it when
***************
*** 1977,2134 **** write_csvlog(ErrorData *edata)
  	initStringInfo(&buf);
  
  	/*
! 	 * timestamp with milliseconds
! 	 *
! 	 * Check if the timestamp is already calculated for the syslog message,
! 	 * and use it if so.  Otherwise, get the current timestamp.  This is done
! 	 * to put same timestamp in both syslog and csvlog messages.
  	 */
! 	if (formatted_log_time[0] == '\0')
! 		setup_formatted_log_time();
  
! 	appendStringInfoString(&buf, formatted_log_time);
! 	appendStringInfoChar(&buf, ',');
  
! 	/* username */
! 	if (MyProcPort)
! 		appendCSVLiteral(&buf, MyProcPort->user_name);
! 	appendStringInfoChar(&buf, ',');
  
! 	/* database name */
! 	if (MyProcPort)
! 		appendCSVLiteral(&buf, MyProcPort->database_name);
! 	appendStringInfoChar(&buf, ',');
  
! 	/* Process id  */
! 	if (MyProcPid != 0)
! 		appendStringInfo(&buf, "%d", MyProcPid);
! 	appendStringInfoChar(&buf, ',');
  
! 	/* Remote host and port */
! 	if (MyProcPort && MyProcPort->remote_host)
! 	{
! 		appendStringInfoChar(&buf, '"');
! 		appendStringInfoString(&buf, MyProcPort->remote_host);
! 		if (MyProcPort->remote_port && MyProcPort->remote_port[0] != '\0')
! 		{
! 			appendStringInfoChar(&buf, ':');
! 			appendStringInfoString(&buf, MyProcPort->remote_port);
! 		}
! 		appendStringInfoChar(&buf, '"');
! 	}
! 	appendStringInfoChar(&buf, ',');
  
! 	/* session id */
! 	appendStringInfo(&buf, "%lx.%x", (long) MyStartTime, MyProcPid);
! 	appendStringInfoChar(&buf, ',');
  
! 	/* Line number */
! 	appendStringInfo(&buf, "%ld", log_line_number);
! 	appendStringInfoChar(&buf, ',');
  
! 	/* PS display */
! 	if (MyProcPort)
! 	{
! 		StringInfoData msgbuf;
! 		const char *psdisp;
! 		int			displen;
  
! 		initStringInfo(&msgbuf);
  
! 		psdisp = get_ps_display(&displen);
! 		appendBinaryStringInfo(&msgbuf, psdisp, displen);
! 		appendCSVLiteral(&buf, msgbuf.data);
  
! 		pfree(msgbuf.data);
! 	}
! 	appendStringInfoChar(&buf, ',');
  
! 	/* session start timestamp */
! 	if (formatted_start_time[0] == '\0')
! 		setup_formatted_start_time();
! 	appendStringInfoString(&buf, formatted_start_time);
! 	appendStringInfoChar(&buf, ',');
  
! 	/* Virtual transaction id */
! 	/* keep VXID format in sync with lockfuncs.c */
! 	if (MyProc != NULL && MyProc->backendId != InvalidBackendId)
! 		appendStringInfo(&buf, "%d/%u", MyProc->backendId, MyProc->lxid);
! 	appendStringInfoChar(&buf, ',');
  
! 	/* Transaction id */
! 	appendStringInfo(&buf, "%u", GetTopTransactionIdIfAny());
! 	appendStringInfoChar(&buf, ',');
  
! 	/* Error severity */
! 	appendStringInfoString(&buf, error_severity(edata->elevel));
! 	appendStringInfoChar(&buf, ',');
  
! 	/* SQL state code */
! 	appendStringInfoString(&buf, unpack_sql_state(edata->sqlerrcode));
! 	appendStringInfoChar(&buf, ',');
  
! 	/* errmessage */
! 	appendCSVLiteral(&buf, edata->message);
! 	appendStringInfoChar(&buf, ',');
  
! 	/* errdetail or errdetail_log */
! 	if (edata->detail_log)
! 		appendCSVLiteral(&buf, edata->detail_log);
! 	else
! 		appendCSVLiteral(&buf, edata->detail);
! 	appendStringInfoChar(&buf, ',');
  
! 	/* errhint */
! 	appendCSVLiteral(&buf, edata->hint);
! 	appendStringInfoChar(&buf, ',');
  
! 	/* internal query */
! 	appendCSVLiteral(&buf, edata->internalquery);
! 	appendStringInfoChar(&buf, ',');
  
! 	/* if printed internal query, print internal pos too */
! 	if (edata->internalpos > 0 && edata->internalquery != NULL)
! 		appendStringInfo(&buf, "%d", edata->internalpos);
! 	appendStringInfoChar(&buf, ',');
  
! 	/* errcontext */
! 	appendCSVLiteral(&buf, edata->context);
! 	appendStringInfoChar(&buf, ',');
  
! 	/* user query --- only reported if not disabled by the caller */
! 	if (is_log_level_output(edata->elevel, log_min_error_statement) &&
! 		debug_query_string != NULL &&
! 		!edata->hide_stmt)
! 		print_stmt = true;
! 	if (print_stmt)
! 		appendCSVLiteral(&buf, debug_query_string);
! 	appendStringInfoChar(&buf, ',');
! 	if (print_stmt && edata->cursorpos > 0)
! 		appendStringInfo(&buf, "%d", edata->cursorpos);
! 	appendStringInfoChar(&buf, ',');
! 
! 	/* file error location */
! 	if (Log_error_verbosity >= PGERROR_VERBOSE)
! 	{
! 		StringInfoData msgbuf;
! 
! 		initStringInfo(&msgbuf);
! 
! 		if (edata->funcname && edata->filename)
! 			appendStringInfo(&msgbuf, "%s, %s:%d",
! 							 edata->funcname, edata->filename,
! 							 edata->lineno);
! 		else if (edata->filename)
! 			appendStringInfo(&msgbuf, "%s:%d",
! 							 edata->filename, edata->lineno);
! 		appendCSVLiteral(&buf, msgbuf.data);
! 		pfree(msgbuf.data);
  	}
- 	appendStringInfoChar(&buf, ',');
- 
- 	/* application name */
- 	if (application_name)
- 		appendCSVLiteral(&buf, application_name);
  
  	appendStringInfoChar(&buf, '\n');
  
--- 2169,2427 ----
  	initStringInfo(&buf);
  
  	/*
! 	 * Loop through the fields requested by the user, in the order requested, in
! 	 * the log_csv_fields GUC.
  	 */
! 	foreach(l, csv_log_fields)
! 	{
! 		switch (lfirst_int(l))
! 		{
! 			case CSVLOG_LOG_TIME:
! 				{
! 					/*
! 					 * timestamp with milliseconds
! 					 *
! 					 * Check if the timestamp is already calculated for the syslog message,
! 					 * and use it if so.  Otherwise, get the current timestamp.  This is done
! 					 * to put same timestamp in both syslog and csvlog messages.
! 					 */
! 					if (formatted_log_time[0] == '\0')
! 						setup_formatted_log_time();
! 
! 					appendStringInfoString(&buf, formatted_log_time);
! 					appendStringInfoChar(&buf, ',');
! 				}
! 				break;
  
! 			case CSVLOG_USER_NAME:
! 				{
! 					/* session username, as done for %u */
! 					if (*session_auth != '\0')
! 						appendCSVLiteral(&buf, session_auth);
! 					else
! 						/* username */
! 						if (MyProcPort)
! 						{
! 							const char *username = MyProcPort->user_name;
! 							if (username == NULL || *username == '\0')
! 								username = _("[unknown]");
! 							appendCSVLiteral(&buf, MyProcPort->user_name);
! 						}
! 					appendStringInfoChar(&buf, ',');
! 				}
! 				break;
  
! 			case CSVLOG_ROLE_NAME:
! 				/* current role, not updated if someone renames it in another
! 				 * session, of course */
! 				appendCSVLiteral(&buf, show_role());
! 				appendStringInfoChar(&buf, ',');
! 				break;
  
! 			case CSVLOG_DATABASE_NAME:
! 				{
! 					/* database name */
! 					if (MyProcPort)
! 						appendCSVLiteral(&buf, MyProcPort->database_name);
! 					appendStringInfoChar(&buf, ',');
! 				}
! 				break;
  
! 			case CSVLOG_PROCESS_ID:
! 				{
! 					/* Process id  */
! 					if (MyProcPid != 0)
! 						appendStringInfo(&buf, "%d", MyProcPid);
! 					appendStringInfoChar(&buf, ',');
! 				}
! 				break;
  
! 			case CSVLOG_CONNECTION_FROM:
! 				{
! 					/* Remote host and port */
! 					if (MyProcPort && MyProcPort->remote_host)
! 					{
! 						appendStringInfoChar(&buf, '"');
! 						appendStringInfoString(&buf, MyProcPort->remote_host);
! 						if (MyProcPort->remote_port && MyProcPort->remote_port[0] != '\0')
! 						{
! 							appendStringInfoChar(&buf, ':');
! 							appendStringInfoString(&buf, MyProcPort->remote_port);
! 						}
! 						appendStringInfoChar(&buf, '"');
! 					}
! 					appendStringInfoChar(&buf, ',');
! 				}
! 				break;
  
! 			case CSVLOG_SESSION_ID:
! 				/* session id */
! 				appendStringInfo(&buf, "%lx.%x", (long) MyStartTime, MyProcPid);
! 				appendStringInfoChar(&buf, ',');
! 				break;
  
! 			case CSVLOG_SESSION_LINE_NUM:
! 				/* Line number */
! 				appendStringInfo(&buf, "%ld", log_line_number);
! 				appendStringInfoChar(&buf, ',');
! 				break;
  
! 			case CSVLOG_COMMAND_TAG:
! 				{
! 					/* PS display */
! 					if (MyProcPort)
! 					{
! 						StringInfoData msgbuf;
! 						const char *psdisp;
! 						int			displen;
! 
! 						initStringInfo(&msgbuf);
! 
! 						psdisp = get_ps_display(&displen);
! 						appendBinaryStringInfo(&msgbuf, psdisp, displen);
! 						appendCSVLiteral(&buf, msgbuf.data);
! 
! 						pfree(msgbuf.data);
! 					}
! 					appendStringInfoChar(&buf, ',');
! 				}
! 				break;
  
! 			case CSVLOG_SESSION_START_TIME:
! 				{
! 					/* session start timestamp */
! 					if (formatted_start_time[0] == '\0')
! 						setup_formatted_start_time();
! 					appendStringInfoString(&buf, formatted_start_time);
! 					appendStringInfoChar(&buf, ',');
! 				}
! 				break;
  
! 			case CSVLOG_VIRTUAL_TRANSACTION_ID:
! 				{
! 					/* Virtual transaction id */
! 					/* keep VXID format in sync with lockfuncs.c */
! 					if (MyProc != NULL && MyProc->backendId != InvalidBackendId)
! 						appendStringInfo(&buf, "%d/%u", MyProc->backendId, MyProc->lxid);
! 					appendStringInfoChar(&buf, ',');
! 				}
! 				break;
  
! 			case CSVLOG_TRANSACTION_ID:
! 				/* Transaction id */
! 				appendStringInfo(&buf, "%u", GetTopTransactionIdIfAny());
! 				appendStringInfoChar(&buf, ',');
! 				break;
  
! 			case CSVLOG_ERROR_SEVERITY:
! 				/* Error severity */
! 				appendStringInfoString(&buf, error_severity(edata->elevel));
! 				appendStringInfoChar(&buf, ',');
! 				break;
  
! 			case CSVLOG_SQL_STATE_CODE:
! 				/* SQL state code */
! 				appendStringInfoString(&buf, unpack_sql_state(edata->sqlerrcode));
! 				appendStringInfoChar(&buf, ',');
! 				break;
  
! 			case CSVLOG_MESSAGE:
! 				/* errmessage */
! 				appendCSVLiteral(&buf, edata->message);
! 				appendStringInfoChar(&buf, ',');
! 				break;
  
! 			case CSVLOG_DETAIL:
! 				{
! 					/* errdetail or errdetail_log */
! 					if (edata->detail_log)
! 						appendCSVLiteral(&buf, edata->detail_log);
! 					else
! 						appendCSVLiteral(&buf, edata->detail);
! 					appendStringInfoChar(&buf, ',');
! 				}
! 				break;
  
! 			case CSVLOG_HINT:
! 				/* errhint */
! 				appendCSVLiteral(&buf, edata->hint);
! 				appendStringInfoChar(&buf, ',');
! 				break;
  
! 			case CSVLOG_INTERNAL_QUERY:
! 				/* internal query */
! 				appendCSVLiteral(&buf, edata->internalquery);
! 				appendStringInfoChar(&buf, ',');
! 				break;
  
! 			case CSVLOG_INTERNAL_QUERY_POS:
! 				{
! 					/* if printed internal query, print internal pos too */
! 					if (edata->internalpos > 0 && edata->internalquery != NULL)
! 						appendStringInfo(&buf, "%d", edata->internalpos);
! 					appendStringInfoChar(&buf, ',');
! 				}
! 				break;
  
! 			case CSVLOG_CONTEXT:
! 				/* errcontext */
! 				appendCSVLiteral(&buf, edata->context);
! 				appendStringInfoChar(&buf, ',');
! 				break;
  
! 			case CSVLOG_QUERY:
! 				{
! 					/* user query --- only reported if not disabled by the caller */
! 					if (is_log_level_output(edata->elevel, log_min_error_statement) &&
! 						debug_query_string != NULL &&
! 						!edata->hide_stmt)
! 						print_stmt = true;
! 					if (print_stmt)
! 						appendCSVLiteral(&buf, debug_query_string);
! 					appendStringInfoChar(&buf, ',');
! 				}
! 				break;
  
! 			case CSVLOG_QUERY_POS:
! 				{
! 					if (print_stmt && edata->cursorpos > 0)
! 						appendStringInfo(&buf, "%d", edata->cursorpos);
! 					appendStringInfoChar(&buf, ',');
! 				}
! 				break;
  
! 			case CSVLOG_LOCATION:
! 				{
! 					/* file error location */
! 					if (Log_error_verbosity >= PGERROR_VERBOSE)
! 					{
! 						StringInfoData msgbuf;
! 
! 						initStringInfo(&msgbuf);
! 
! 						if (edata->funcname && edata->filename)
! 							appendStringInfo(&msgbuf, "%s, %s:%d",
! 											 edata->funcname, edata->filename,
! 											 edata->lineno);
! 						else if (edata->filename)
! 							appendStringInfo(&msgbuf, "%s:%d",
! 											 edata->filename, edata->lineno);
! 						appendCSVLiteral(&buf, msgbuf.data);
! 						pfree(msgbuf.data);
! 					}
! 					appendStringInfoChar(&buf, ',');
! 				}
! 				break;
  
! 			case CSVLOG_APPLICATION_NAME:
! 				{
! 					/* application name */
! 					if (application_name)
! 						appendCSVLiteral(&buf, application_name);
! 				}
! 				break;
! 		}
  	}
  
  	appendStringInfoChar(&buf, '\n');
  
***************
*** 2139,2144 **** write_csvlog(ErrorData *edata)
--- 2432,2439 ----
  		write_pipe_chunks(buf.data, buf.len, LOG_DESTINATION_CSVLOG);
  
  	pfree(buf.data);
+ 
+ 	return;
  }
  
  /*
*** a/src/backend/utils/misc/guc.c
--- b/src/backend/utils/misc/guc.c
***************
*** 63,68 ****
--- 63,69 ----
  #include "tsearch/ts_cache.h"
  #include "utils/builtins.h"
  #include "utils/bytea.h"
+ #include "utils/elog.h"
  #include "utils/guc_tables.h"
  #include "utils/memutils.h"
  #include "utils/pg_locale.h"
***************
*** 190,195 **** static char *config_enum_get_options(struct config_enum * record,
--- 191,199 ----
  						const char *prefix, const char *suffix,
  						const char *separator);
  
+ /* Needs to be defined here because elog.h can't #include guc.h */
+ extern const char *assign_log_csv_fields(const char *newval,
+                 bool doit, GucSource source);
  
  /*
   * Options for enum values defined in this module.
***************
*** 2287,2292 **** static struct config_string ConfigureNamesString[] =
--- 2291,2307 ----
  	},
  
  	{
+ 		{"log_csv_fields", PGC_POSTMASTER, LOGGING_WHAT,
+ 			gettext_noop("Controls fields logged to CSV logfiles."),
+ 			gettext_noop("If blank, the default set of fields is used."),
+ 			GUC_LIST_INPUT
+ 		},
+ 		&Log_csv_fields,
+ 		"log_time, user_name, database_name, process_id, connection_from, session_id, session_line_num, command_tag, session_start_time, virtual_transaction_id, transaction_id, error_severity, sql_state_code, message, detail, hint, internal_query, internal_query_pos, context, query, query_pos, location, application_name",
+ 		assign_log_csv_fields, NULL
+ 	},
+ 
+ 	{
  		{"log_timezone", PGC_SIGHUP, LOGGING_WHAT,
  			gettext_noop("Sets the time zone to use in log messages."),
  			NULL
***************
*** 3436,3441 **** InitializeGUCOptions(void)
--- 3451,3462 ----
  	pg_timezone_pre_initialize();
  
  	/*
+ 	 * Ditto for log_csv_fields, have to set it to something before we get
+ 	 * too far along.
+ 	 */
+ 	build_default_csvlog_list();
+ 
+ 	/*
  	 * Build sorted array of all GUC variables.
  	 */
  	build_guc_variables();
*** a/src/backend/utils/misc/postgresql.conf.sample
--- b/src/backend/utils/misc/postgresql.conf.sample
***************
*** 377,382 ****
--- 377,386 ----
  					#        processes
  					#   %% = '%'
  					# e.g. '<%u%%%d> '
+ 
+ # fields to include in the CSV log output
+ #log_csv_fields = 'log_time, user_name, database_name, process_id, connection_from, session_id, session_line_num, command_tag, session_start_time, virtual_transaction_id, transaction_id, error_severity, sql_state_code, message, detail, hint, internal_query, internal_query_pos, context, query, query_pos, location, application_name'
+ 
  #log_lock_waits = off			# log lock waits >= deadlock_timeout
  #log_statement = 'none'			# none, ddl, mod, all
  #log_temp_files = -1			# log temporary files equal or larger
*** a/src/include/utils/elog.h
--- b/src/include/utils/elog.h
***************
*** 330,337 **** typedef enum
--- 330,366 ----
  
  extern int	Log_error_verbosity;
  extern char *Log_line_prefix;
+ extern char *Log_csv_fields;
  extern int	Log_destination;
  
+ typedef enum LogCSVFields
+ {
+ 	CSVLOG_LOG_TIME,
+ 	CSVLOG_USER_NAME,
+ 	CSVLOG_ROLE_NAME,
+ 	CSVLOG_DATABASE_NAME,
+ 	CSVLOG_PROCESS_ID,
+ 	CSVLOG_CONNECTION_FROM,
+ 	CSVLOG_SESSION_ID,
+ 	CSVLOG_SESSION_LINE_NUM,
+ 	CSVLOG_COMMAND_TAG,
+ 	CSVLOG_SESSION_START_TIME,
+ 	CSVLOG_VIRTUAL_TRANSACTION_ID,
+ 	CSVLOG_TRANSACTION_ID,
+ 	CSVLOG_ERROR_SEVERITY,
+ 	CSVLOG_SQL_STATE_CODE,
+ 	CSVLOG_MESSAGE,
+ 	CSVLOG_DETAIL,
+ 	CSVLOG_HINT,
+ 	CSVLOG_INTERNAL_QUERY,
+ 	CSVLOG_INTERNAL_QUERY_POS,
+ 	CSVLOG_CONTEXT,
+ 	CSVLOG_QUERY,
+ 	CSVLOG_QUERY_POS,
+ 	CSVLOG_LOCATION,
+ 	CSVLOG_APPLICATION_NAME
+ } LogCSVFields;
+ 
  /* Log destination bitmap */
  #define LOG_DESTINATION_STDERR	 1
  #define LOG_DESTINATION_SYSLOG	 2
***************
*** 343,348 **** extern void DebugFileOpen(void);
--- 372,382 ----
  extern char *unpack_sql_state(int sql_state);
  extern bool in_error_recursion_trouble(void);
  
+ /* Used by guc.c to set up the default set of
+  * csv fields to log
+  */
+ extern void build_default_csvlog_list(void);
+ 
  #ifdef HAVE_SYSLOG
  extern void set_syslog_parameters(const char *ident, int facility);
  #endif
*** a/src/tools/pgindent/typedefs.list
--- b/src/tools/pgindent/typedefs.list
***************
*** 854,859 **** LockTagType
--- 854,860 ----
  LockTupleMode
  LockingClause
  LogStmtLevel
+ LogCSVFields
  LogicalTape
  LogicalTapeSet
  MAGIC

*** a/doc/src/sgml/config.sgml
--- b/doc/src/sgml/config.sgml
***************
*** 3504,3510 **** local0.*    /var/log/postgresql
              </row>
              <row>
               <entry><literal>%u</literal></entry>
!              <entry>User name</entry>
               <entry>yes</entry>
              </row>
              <row>
--- 3504,3523 ----
              </row>
              <row>
               <entry><literal>%u</literal></entry>
!              <entry>Session user name, typically the user name which was used
!              to authenticate to <productname>PostgreSQL</productname> with,
!              but can be changed by a superuser, see <command>SET SESSION
!              AUTHORIZATION</></entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>%U</literal></entry>
!              <entry>Current role name, when set with <command>SET ROLE</>;
!              the current role identifier is relevant for permission checking;
!              Returns 'none' if the current role matches the session user.
!              Note: Log messages from inside <literal>SECURITY DEFINER</>
!              functions will show the calling role, not the effective role
!              inside the <literal>SECURITY DEFINER</> function</entry>
               <entry>yes</entry>
              </row>
              <row>
***************
*** 3621,3626 **** FROM pg_stat_activity;
--- 3634,3662 ----
        </listitem>
       </varlistentry>
  
+      <varlistentry id="guc-log-csv-fields" xreflabel="log_csv_fields">
+       <term><varname>log_csv_fields</varname> (<type>string</type>)</term>
+       <indexterm>
+        <primary><varname>log_csv_fields</> configuration parameter</primary>
+       </indexterm>
+       <listitem>
+        <para>
+         Controls the set and order of the fields which are written out in
+         the CSV-format log file.
+ 
+         The default is: log_time, user_name, database_name, process_id,
+         connection_from, session_id, session_line_num, command_tag,
+         session_start_time, virtual_transaction_id, transaction_id,
+         error_severity, sql_state_code, message, detail, hint,
+         internal_query, internal_query_pos, context, query, query_pos,
+         location, application_name
+ 
+         For details on what these fields are, refer to the log_line_prefix
+         and CSV logging documentation.
+        </para>
+       </listitem>
+      </varlistentry>
+ 
       <varlistentry id="guc-log-lock-waits" xreflabel="log_lock_waits">
        <term><varname>log_lock_waits</varname> (<type>boolean</type>)</term>
        <indexterm>
***************
*** 3728,3761 **** FROM pg_stat_activity;
          Including <literal>csvlog</> in the <varname>log_destination</> list
          provides a convenient way to import log files into a database table.
          This option emits log lines in comma-separated-values
!         (<acronym>CSV</>) format,
!         with these columns:
!         timestamp with milliseconds,
!         user name,
!         database name,
!         process ID,
!         client host:port number,
!         session ID,
!         per-session line number,
!         command tag,
!         session start time,
!         virtual transaction ID,
!         regular transaction ID,
!         error severity,
!         SQLSTATE code,
!         error message,
!         error message detail,
!         hint,
!         internal query that led to the error (if any),
!         character count of the error position therein,
!         error context,
!         user query that led to the error (if any and enabled by
!         <varname>log_min_error_statement</>),
!         character count of the error position therein,
!         location of the error in the PostgreSQL source code
          (if <varname>log_error_verbosity</> is set to <literal>verbose</>),
!         and application name.
!         Here is a sample table definition for storing CSV-format log output:
  
  <programlisting>
  CREATE TABLE postgres_log
--- 3764,3833 ----
          Including <literal>csvlog</> in the <varname>log_destination</> list
          provides a convenient way to import log files into a database table.
          This option emits log lines in comma-separated-values
!         (<acronym>CSV</>) format.  These columns may be included in the CSV
!         output:
!         log_time,                   # timestamp with milliseconds
!         user_name,                  # session user name
!         role_name,                  # current role name
!         database_name,              # database name
!         process_id,                 # process ID
!         connection_from,            # client host:port number
!         session_id,                 # session ID
!         session_line_number,        # per-session line number
!         command_tag,                # command tag
!         session_start_time,         # session start time
!         virtual_transaction_id,     # virtual transaction ID
!         transaction_id,             # regular transaction ID
!         error_severity,             # error severity
!         sql_state_code,             # SQLSTATE code
!         message,                    # error message
!         detail,                     # error message detail
!         hint,                       # hint
!         internal_query,             # internal query that led to the error (if any)
!         internal_query_pos,         # character count of the error position therein
!         context,                    # error context
!         query,             # user query that led to the error (if any and enabled by
!         <varname>log_min_error_statement</>)
!         query_pos,         # character count of the error position therein
!         location,          # location of the error in the PostgreSQL source code
          (if <varname>log_error_verbosity</> is set to <literal>verbose</>),
!         application_name            # application name
! 
!         The default set of columns does not include current role name, and
!         is currently:
! 
!         log_time,
!         user_name,
!         database_name,
!         process_id,
!         connection_from,
!         session_id,
!         session_line_num,
!         command_tag,
!         session_start_time,
!         virtual_transaction_id,
!         transaction_id,
!         error_severity,
!         sql_state_code,
!         message,
!         detail,
!         hint,
!         internal_query,
!         internal_query_pos,
!         context,
!         query,
!         query_pos,
!         location,
!         application_name
! 
!         The set of columns to be included, and their order, in the CSV
!         output can be controlled using the <varname>log_csv_fields</> option.
! 
!         For additional details on the definition of the above columns, refer
!         to the documentation for <varname>log_line_prefix</>.
! 
!         Here is a sample table definition for storing the default CSV-format
!         log output:
  
  <programlisting>
  CREATE TABLE postgres_log
*** a/src/backend/commands/variable.c
--- b/src/backend/commands/variable.c
***************
*** 760,765 **** assign_session_authorization(const char *value, bool doit, GucSource source)
--- 760,770 ----
  	return result;
  }
  
+ /*
+  * function to return the stored session username, needed because we
+  * can't do catalog lookups when possibly being called after an error,
+  * eg: from elog.c or part of GUC handling.
+  */
  const char *
  show_session_authorization(void)
  {
***************
*** 885,890 **** assign_role(const char *value, bool doit, GucSource source)
--- 890,900 ----
  	return result;
  }
  
+ /*
+  * function to return the stored role username, needed because we
+  * can't do catalog lookups when possibly being called after an error,
+  * eg: from elog.c or part of GUC handling.
+  */
  const char *
  show_role(void)
  {
*** a/src/backend/utils/error/elog.c
--- b/src/backend/utils/error/elog.c
***************
*** 3,8 ****
--- 3,17 ----
   * elog.c
   *	  error logging and reporting
   *
+  * A few comments about situations where error processing is called:
+  *
+  * We need to be cautious of both a performance hit when logging, since
+  * log messages can be generated at a huge rate if every command is being
+  * logged and we also need to watch out for what can happen when we are
+  * trying to log from an aborted transaction.  Specifically, attempting to
+  * do SysCache lookups and possibly use other usually available backend
+  * systems will fail badly when logging from an aborted transaction.
+  *
   * Some notes about recursion and errors during error processing:
   *
   * We need to be robust about recursive-error scenarios --- for example,
***************
*** 59,73 ****
--- 68,85 ----
  
  #include "access/transam.h"
  #include "access/xact.h"
+ #include "commands/variable.h"
  #include "libpq/libpq.h"
  #include "libpq/pqformat.h"
  #include "mb/pg_wchar.h"
  #include "miscadmin.h"
+ #include "nodes/pg_list.h"
  #include "postmaster/postmaster.h"
  #include "postmaster/syslogger.h"
  #include "storage/ipc.h"
  #include "storage/proc.h"
  #include "tcop/tcopprot.h"
+ #include "utils/builtins.h"
  #include "utils/guc.h"
  #include "utils/memutils.h"
  #include "utils/ps_status.h"
***************
*** 93,98 **** extern bool redirection_done;
--- 105,113 ----
  int			Log_error_verbosity = PGERROR_VERBOSE;
  char	   *Log_line_prefix = NULL;		/* format for extra log line info */
  int			Log_destination = LOG_DESTINATION_STDERR;
+ char	   *Log_csv_fields = NULL;
+ 
+ static List *csv_log_fields = NIL;
  
  #ifdef HAVE_SYSLOG
  
***************
*** 161,166 **** static void write_csvlog(ErrorData *edata);
--- 176,186 ----
  static void setup_formatted_log_time(void);
  static void setup_formatted_start_time(void);
  
+ /* extern'd and used from guc.c... */
+ const char *
+ assign_log_csv_fields(const char *newval, bool doit, GucSource source);
+ 
+ 
  
  /*
   * in_error_recursion_trouble --- are we at risk of infinite error recursion?
***************
*** 1817,1831 **** log_line_prefix(StringInfo buf, ErrorData *edata)
  				}
  				break;
  			case 'u':
- 				if (MyProcPort)
  				{
! 					const char *username = MyProcPort->user_name;
! 
! 					if (username == NULL || *username == '\0')
! 						username = _("[unknown]");
! 					appendStringInfoString(buf, username);
  				}
  				break;
  			case 'd':
  				if (MyProcPort)
  				{
--- 1837,1860 ----
  				}
  				break;
  			case 'u':
  				{
! 				const char *session_auth = show_session_authorization();
! 				if (*session_auth != '\0')
! 					appendStringInfoString(buf, session_auth);
! 				else
! 					if (MyProcPort)
! 					{
! 						const char *username = MyProcPort->user_name;
! 
! 						if (username == NULL || *username == '\0')
! 							username = _("[unknown]");
! 						appendStringInfoString(buf, username);
! 					}
  				}
  				break;
+ 			case 'U':
+ 				appendStringInfoString(buf, show_role());
+ 				break;
  			case 'd':
  				if (MyProcPort)
  				{
***************
*** 1921,1926 **** log_line_prefix(StringInfo buf, ErrorData *edata)
--- 1950,2112 ----
  }
  
  /*
+  * Build up the default set of CSV fields to output, in case we need it before
+  * GUC processing is done.
+  *
+  * This is more of a 'safety valve' than anything else,
+  * since GUC processing really should happen before we do any error logging.
+  * We might even want to change this eventually to just not log CSV format logs
+  * if this ever happens, to avoid a discrepency in the CSV log file which would
+  * make it difficult to load into PG.
+  */
+ void
+ build_default_csvlog_list(void)
+ {
+ 	List		*new_csv_fields = NIL;
+ 	MemoryContext oldcontext;
+ 
+ 	oldcontext = MemoryContextSwitchTo(TopMemoryContext);
+ 
+ 	new_csv_fields = lappend_int(new_csv_fields,CSVLOG_LOG_TIME);
+ 	new_csv_fields = lappend_int(new_csv_fields,CSVLOG_USER_NAME);
+ 	new_csv_fields = lappend_int(new_csv_fields,CSVLOG_DATABASE_NAME);
+ 	new_csv_fields = lappend_int(new_csv_fields,CSVLOG_PROCESS_ID);
+ 	new_csv_fields = lappend_int(new_csv_fields,CSVLOG_CONNECTION_FROM);
+ 	new_csv_fields = lappend_int(new_csv_fields,CSVLOG_SESSION_ID);
+ 	new_csv_fields = lappend_int(new_csv_fields,CSVLOG_SESSION_LINE_NUM);
+ 	new_csv_fields = lappend_int(new_csv_fields,CSVLOG_COMMAND_TAG);
+ 	new_csv_fields = lappend_int(new_csv_fields,CSVLOG_SESSION_START_TIME);
+ 	new_csv_fields = lappend_int(new_csv_fields,CSVLOG_VIRTUAL_TRANSACTION_ID);
+ 	new_csv_fields = lappend_int(new_csv_fields,CSVLOG_TRANSACTION_ID);
+ 	new_csv_fields = lappend_int(new_csv_fields,CSVLOG_ERROR_SEVERITY);
+ 	new_csv_fields = lappend_int(new_csv_fields,CSVLOG_SQL_STATE_CODE);
+ 	new_csv_fields = lappend_int(new_csv_fields,CSVLOG_MESSAGE);
+ 	new_csv_fields = lappend_int(new_csv_fields,CSVLOG_DETAIL);
+ 	new_csv_fields = lappend_int(new_csv_fields,CSVLOG_HINT);
+ 	new_csv_fields = lappend_int(new_csv_fields,CSVLOG_INTERNAL_QUERY);
+ 	new_csv_fields = lappend_int(new_csv_fields,CSVLOG_INTERNAL_QUERY_POS);
+ 	new_csv_fields = lappend_int(new_csv_fields,CSVLOG_CONTEXT);
+ 	new_csv_fields = lappend_int(new_csv_fields,CSVLOG_QUERY);
+ 	new_csv_fields = lappend_int(new_csv_fields,CSVLOG_QUERY_POS);
+ 	new_csv_fields = lappend_int(new_csv_fields,CSVLOG_LOCATION);
+ 	new_csv_fields = lappend_int(new_csv_fields,CSVLOG_APPLICATION_NAME);
+ 
+ 	/* put new list in place */
+ 	csv_log_fields = new_csv_fields;
+ 
+ 	MemoryContextSwitchTo(oldcontext);
+ 
+ 	return;
+ }
+ 
+ 
+ /*
+  * Process the list of fields to be sent to the CSV log file
+  */
+ const char *
+ assign_log_csv_fields(const char *newval, bool doit, GucSource source)
+ {
+ 	/* Verify the list is valid */
+ 	List		*new_csv_fields = NIL;
+ 	List		*column_list = NIL;
+ 	ListCell	*l;
+ 	char		*rawstring;
+ 	MemoryContext oldcontext;
+ 
+ 	/* Need a modifyable version to pass to SplitIdentifierString */
+ 	rawstring = pstrdup(newval);
+ 
+     /* Parse string into list of identifiers */
+     if (!SplitIdentifierString(rawstring, ',', &column_list))
+ 	{
+ 		list_free(column_list);
+ 		return NULL;
+ 	}
+ 
+ 	/*
+ 	 * We need the allocations done for the csv_log_fields list to
+ 	 * be preserved, so allocate them in TopMemoryContext.
+ 	 */
+ 	oldcontext = MemoryContextSwitchTo(TopMemoryContext);
+ 
+ 	/*
+ 	 * Loop through all of the fields provided by the user and build
+ 	 * up our new_csv_fields list which will be processed by write_csvlog
+ 	 */
+ 	foreach(l, column_list)
+ 	{
+ 		if (pg_strcasecmp(lfirst(l),"log_time") == 0)
+ 			new_csv_fields = lappend_int(new_csv_fields,CSVLOG_LOG_TIME);
+ 		else if (pg_strcasecmp(lfirst(l),"user_name") == 0)
+ 			new_csv_fields = lappend_int(new_csv_fields,CSVLOG_USER_NAME);
+ 		else if (pg_strcasecmp(lfirst(l),"role_name") == 0)
+ 			new_csv_fields = lappend_int(new_csv_fields,CSVLOG_ROLE_NAME);
+ 		else if (pg_strcasecmp(lfirst(l),"database_name") == 0)
+ 			new_csv_fields = lappend_int(new_csv_fields,CSVLOG_DATABASE_NAME);
+ 		else if (pg_strcasecmp(lfirst(l),"process_id") == 0)
+ 			new_csv_fields = lappend_int(new_csv_fields,CSVLOG_PROCESS_ID);
+ 		else if (pg_strcasecmp(lfirst(l),"connection_from") == 0)
+ 			new_csv_fields = lappend_int(new_csv_fields,CSVLOG_CONNECTION_FROM);
+ 		else if (pg_strcasecmp(lfirst(l),"session_id") == 0)
+ 			new_csv_fields = lappend_int(new_csv_fields,CSVLOG_SESSION_ID);
+ 		else if (pg_strcasecmp(lfirst(l),"session_line_num") == 0)
+ 			new_csv_fields = lappend_int(new_csv_fields,CSVLOG_SESSION_LINE_NUM);
+ 		else if (pg_strcasecmp(lfirst(l),"command_tag") == 0)
+ 			new_csv_fields = lappend_int(new_csv_fields,CSVLOG_COMMAND_TAG);
+ 		else if (pg_strcasecmp(lfirst(l),"session_start_time") == 0)
+ 			new_csv_fields = lappend_int(new_csv_fields,CSVLOG_SESSION_START_TIME);
+ 		else if (pg_strcasecmp(lfirst(l),"virtual_transaction_id") == 0)
+ 			new_csv_fields = lappend_int(new_csv_fields,CSVLOG_VIRTUAL_TRANSACTION_ID);
+ 		else if (pg_strcasecmp(lfirst(l),"transaction_id") == 0)
+ 			new_csv_fields = lappend_int(new_csv_fields,CSVLOG_TRANSACTION_ID);
+ 		else if (pg_strcasecmp(lfirst(l),"error_severity") == 0)
+ 			new_csv_fields = lappend_int(new_csv_fields,CSVLOG_ERROR_SEVERITY);
+ 		else if (pg_strcasecmp(lfirst(l),"sql_state_code") == 0)
+ 			new_csv_fields = lappend_int(new_csv_fields,CSVLOG_SQL_STATE_CODE);
+ 		else if (pg_strcasecmp(lfirst(l),"message") == 0)
+ 			new_csv_fields = lappend_int(new_csv_fields,CSVLOG_MESSAGE);
+ 		else if (pg_strcasecmp(lfirst(l),"detail") == 0)
+ 			new_csv_fields = lappend_int(new_csv_fields,CSVLOG_DETAIL);
+ 		else if (pg_strcasecmp(lfirst(l),"hint") == 0)
+ 			new_csv_fields = lappend_int(new_csv_fields,CSVLOG_HINT);
+ 		else if (pg_strcasecmp(lfirst(l),"internal_query") == 0)
+ 			new_csv_fields = lappend_int(new_csv_fields,CSVLOG_INTERNAL_QUERY);
+ 		else if (pg_strcasecmp(lfirst(l),"internal_query_pos") == 0)
+ 			new_csv_fields = lappend_int(new_csv_fields,CSVLOG_INTERNAL_QUERY_POS);
+ 		else if (pg_strcasecmp(lfirst(l),"context") == 0)
+ 			new_csv_fields = lappend_int(new_csv_fields,CSVLOG_CONTEXT);
+ 		else if (pg_strcasecmp(lfirst(l),"query") == 0)
+ 			new_csv_fields = lappend_int(new_csv_fields,CSVLOG_QUERY);
+ 		else if (pg_strcasecmp(lfirst(l),"query_pos") == 0)
+ 			new_csv_fields = lappend_int(new_csv_fields,CSVLOG_QUERY_POS);
+ 		else if (pg_strcasecmp(lfirst(l),"location") == 0)
+ 			new_csv_fields = lappend_int(new_csv_fields,CSVLOG_LOCATION);
+ 		else if (pg_strcasecmp(lfirst(l),"application_name") == 0)
+ 			new_csv_fields = lappend_int(new_csv_fields,CSVLOG_APPLICATION_NAME);
+ 		else
+ 		{
+ 			/* handle error, might need to do better than this */
+ 			return NULL;
+ 		}
+ 	}
+ 
+ 	if (doit)
+ 	{
+ 		/* put new list in place */
+ 		List *old_list = csv_log_fields;
+ 
+ 		csv_log_fields = new_csv_fields;
+ 
+ 		list_free(old_list);
+ 	}
+ 
+ 	/* Switch back to the calling context */
+ 	MemoryContextSwitchTo(oldcontext);
+ 
+ 	return newval;
+ }
+ 
+ /*
   * append a CSV'd version of a string to a StringInfo
   * We use the PostgreSQL defaults for CSV, i.e. quote = escape = '"'
   * If it's NULL, append nothing.
***************
*** 1946,1957 **** appendCSVLiteral(StringInfo buf, const char *data)
  }
  
  /*
!  * Constructs the error message, depending on the Errordata it gets, in a CSV
!  * format which is described in doc/src/sgml/config.sgml.
   */
  static void
  write_csvlog(ErrorData *edata)
  {
  	StringInfoData buf;
  	bool		print_stmt = false;
  
--- 2132,2145 ----
  }
  
  /*
!  * Constructs the error message, depending on the Errordata it gets, in the CSV
!  * format requested by the user, based on the log_csv_fields GUC.
   */
  static void
  write_csvlog(ErrorData *edata)
  {
+ 	int			num_fields;
+ 	int			curr_field = 0;
  	StringInfoData buf;
  	bool		print_stmt = false;
  
***************
*** 1961,1966 **** write_csvlog(ErrorData *edata)
--- 2149,2158 ----
  	/* has counter been reset in current process? */
  	static int	log_my_pid = 0;
  
+ 	ListCell	*l;
+ 
+ 	const char *session_auth = show_session_authorization();
+ 
  	/*
  	 * This is one of the few places where we'd rather not inherit a static
  	 * variable's value from the postmaster.  But since we will, reset it when
***************
*** 1977,2134 **** write_csvlog(ErrorData *edata)
  	initStringInfo(&buf);
  
  	/*
! 	 * timestamp with milliseconds
! 	 *
! 	 * Check if the timestamp is already calculated for the syslog message,
! 	 * and use it if so.  Otherwise, get the current timestamp.  This is done
! 	 * to put same timestamp in both syslog and csvlog messages.
  	 */
! 	if (formatted_log_time[0] == '\0')
! 		setup_formatted_log_time();
  
! 	appendStringInfoString(&buf, formatted_log_time);
! 	appendStringInfoChar(&buf, ',');
  
! 	/* username */
! 	if (MyProcPort)
! 		appendCSVLiteral(&buf, MyProcPort->user_name);
! 	appendStringInfoChar(&buf, ',');
  
! 	/* database name */
! 	if (MyProcPort)
! 		appendCSVLiteral(&buf, MyProcPort->database_name);
! 	appendStringInfoChar(&buf, ',');
  
! 	/* Process id  */
! 	if (MyProcPid != 0)
! 		appendStringInfo(&buf, "%d", MyProcPid);
! 	appendStringInfoChar(&buf, ',');
  
! 	/* Remote host and port */
! 	if (MyProcPort && MyProcPort->remote_host)
! 	{
! 		appendStringInfoChar(&buf, '"');
! 		appendStringInfoString(&buf, MyProcPort->remote_host);
! 		if (MyProcPort->remote_port && MyProcPort->remote_port[0] != '\0')
! 		{
! 			appendStringInfoChar(&buf, ':');
! 			appendStringInfoString(&buf, MyProcPort->remote_port);
! 		}
! 		appendStringInfoChar(&buf, '"');
! 	}
! 	appendStringInfoChar(&buf, ',');
  
! 	/* session id */
! 	appendStringInfo(&buf, "%lx.%x", (long) MyStartTime, MyProcPid);
! 	appendStringInfoChar(&buf, ',');
  
! 	/* Line number */
! 	appendStringInfo(&buf, "%ld", log_line_number);
! 	appendStringInfoChar(&buf, ',');
  
! 	/* PS display */
! 	if (MyProcPort)
! 	{
! 		StringInfoData msgbuf;
! 		const char *psdisp;
! 		int			displen;
  
! 		initStringInfo(&msgbuf);
  
! 		psdisp = get_ps_display(&displen);
! 		appendBinaryStringInfo(&msgbuf, psdisp, displen);
! 		appendCSVLiteral(&buf, msgbuf.data);
  
! 		pfree(msgbuf.data);
! 	}
! 	appendStringInfoChar(&buf, ',');
  
! 	/* session start timestamp */
! 	if (formatted_start_time[0] == '\0')
! 		setup_formatted_start_time();
! 	appendStringInfoString(&buf, formatted_start_time);
! 	appendStringInfoChar(&buf, ',');
  
! 	/* Virtual transaction id */
! 	/* keep VXID format in sync with lockfuncs.c */
! 	if (MyProc != NULL && MyProc->backendId != InvalidBackendId)
! 		appendStringInfo(&buf, "%d/%u", MyProc->backendId, MyProc->lxid);
! 	appendStringInfoChar(&buf, ',');
  
! 	/* Transaction id */
! 	appendStringInfo(&buf, "%u", GetTopTransactionIdIfAny());
! 	appendStringInfoChar(&buf, ',');
  
! 	/* Error severity */
! 	appendStringInfoString(&buf, error_severity(edata->elevel));
! 	appendStringInfoChar(&buf, ',');
  
! 	/* SQL state code */
! 	appendStringInfoString(&buf, unpack_sql_state(edata->sqlerrcode));
! 	appendStringInfoChar(&buf, ',');
  
! 	/* errmessage */
! 	appendCSVLiteral(&buf, edata->message);
! 	appendStringInfoChar(&buf, ',');
  
! 	/* errdetail or errdetail_log */
! 	if (edata->detail_log)
! 		appendCSVLiteral(&buf, edata->detail_log);
! 	else
! 		appendCSVLiteral(&buf, edata->detail);
! 	appendStringInfoChar(&buf, ',');
  
! 	/* errhint */
! 	appendCSVLiteral(&buf, edata->hint);
! 	appendStringInfoChar(&buf, ',');
  
! 	/* internal query */
! 	appendCSVLiteral(&buf, edata->internalquery);
! 	appendStringInfoChar(&buf, ',');
  
! 	/* if printed internal query, print internal pos too */
! 	if (edata->internalpos > 0 && edata->internalquery != NULL)
! 		appendStringInfo(&buf, "%d", edata->internalpos);
! 	appendStringInfoChar(&buf, ',');
  
! 	/* errcontext */
! 	appendCSVLiteral(&buf, edata->context);
! 	appendStringInfoChar(&buf, ',');
  
! 	/* user query --- only reported if not disabled by the caller */
! 	if (is_log_level_output(edata->elevel, log_min_error_statement) &&
! 		debug_query_string != NULL &&
! 		!edata->hide_stmt)
! 		print_stmt = true;
! 	if (print_stmt)
! 		appendCSVLiteral(&buf, debug_query_string);
! 	appendStringInfoChar(&buf, ',');
! 	if (print_stmt && edata->cursorpos > 0)
! 		appendStringInfo(&buf, "%d", edata->cursorpos);
! 	appendStringInfoChar(&buf, ',');
! 
! 	/* file error location */
! 	if (Log_error_verbosity >= PGERROR_VERBOSE)
! 	{
! 		StringInfoData msgbuf;
! 
! 		initStringInfo(&msgbuf);
! 
! 		if (edata->funcname && edata->filename)
! 			appendStringInfo(&msgbuf, "%s, %s:%d",
! 							 edata->funcname, edata->filename,
! 							 edata->lineno);
! 		else if (edata->filename)
! 			appendStringInfo(&msgbuf, "%s:%d",
! 							 edata->filename, edata->lineno);
! 		appendCSVLiteral(&buf, msgbuf.data);
! 		pfree(msgbuf.data);
! 	}
! 	appendStringInfoChar(&buf, ',');
  
! 	/* application name */
! 	if (application_name)
! 		appendCSVLiteral(&buf, application_name);
  
  	appendStringInfoChar(&buf, '\n');
  
--- 2169,2437 ----
  	initStringInfo(&buf);
  
  	/*
! 	 * Get the number of fields, so we make sure to *not* include a comma
! 	 * after the last field.
  	 */
! 	num_fields = list_length(csv_log_fields);
  
! 	/*
! 	 * Loop through the fields requested by the user, in the order requested, in
! 	 * the log_csv_fields GUC.
! 	 */
! 	foreach(l, csv_log_fields)
! 	{
! 		/* Update which field we are on, needed to check if it's the last field */
! 		curr_field++;
  
! 		switch (lfirst_int(l))
! 		{
! 			case CSVLOG_LOG_TIME:
! 				{
! 					/*
! 					 * timestamp with milliseconds
! 					 *
! 					 * Check if the timestamp is already calculated for the syslog message,
! 					 * and use it if so.  Otherwise, get the current timestamp.  This is done
! 					 * to put same timestamp in both syslog and csvlog messages.
! 					 */
! 					if (formatted_log_time[0] == '\0')
! 						setup_formatted_log_time();
! 
! 					appendStringInfoString(&buf, formatted_log_time);
! 					if (curr_field != num_fields) appendStringInfoChar(&buf, ',');
! 				}
! 				break;
  
! 			case CSVLOG_USER_NAME:
! 				{
! 					/* session username, as done for %u */
! 					if (*session_auth != '\0')
! 						appendCSVLiteral(&buf, session_auth);
! 					else
! 						/* username */
! 						if (MyProcPort)
! 						{
! 							const char *username = MyProcPort->user_name;
! 							if (username == NULL || *username == '\0')
! 								username = _("[unknown]");
! 							appendCSVLiteral(&buf, MyProcPort->user_name);
! 						}
! 					if (curr_field != num_fields) appendStringInfoChar(&buf, ',');
! 				}
! 				break;
  
! 			case CSVLOG_ROLE_NAME:
! 				/* current role, not updated if someone renames it in another
! 				 * session, of course */
! 				appendCSVLiteral(&buf, show_role());
! 				if (curr_field != num_fields) appendStringInfoChar(&buf, ',');
! 				break;
  
! 			case CSVLOG_DATABASE_NAME:
! 				{
! 					/* database name */
! 					if (MyProcPort)
! 						appendCSVLiteral(&buf, MyProcPort->database_name);
! 					if (curr_field != num_fields) appendStringInfoChar(&buf, ',');
! 				}
! 				break;
  
! 			case CSVLOG_PROCESS_ID:
! 				{
! 					/* Process id  */
! 					if (MyProcPid != 0)
! 						appendStringInfo(&buf, "%d", MyProcPid);
! 					if (curr_field != num_fields) appendStringInfoChar(&buf, ',');
! 				}
! 				break;
  
! 			case CSVLOG_CONNECTION_FROM:
! 				{
! 					/* Remote host and port */
! 					if (MyProcPort && MyProcPort->remote_host)
! 					{
! 						appendStringInfoChar(&buf, '"');
! 						appendStringInfoString(&buf, MyProcPort->remote_host);
! 						if (MyProcPort->remote_port && MyProcPort->remote_port[0] != '\0')
! 						{
! 							appendStringInfoChar(&buf, ':');
! 							appendStringInfoString(&buf, MyProcPort->remote_port);
! 						}
! 						appendStringInfoChar(&buf, '"');
! 					}
! 					if (curr_field != num_fields) appendStringInfoChar(&buf, ',');
! 				}
! 				break;
  
! 			case CSVLOG_SESSION_ID:
! 				/* session id */
! 				appendStringInfo(&buf, "%lx.%x", (long) MyStartTime, MyProcPid);
! 				if (curr_field != num_fields) appendStringInfoChar(&buf, ',');
! 				break;
  
! 			case CSVLOG_SESSION_LINE_NUM:
! 				/* Line number */
! 				appendStringInfo(&buf, "%ld", log_line_number);
! 				if (curr_field != num_fields) appendStringInfoChar(&buf, ',');
! 				break;
  
! 			case CSVLOG_COMMAND_TAG:
! 				{
! 					/* PS display */
! 					if (MyProcPort)
! 					{
! 						StringInfoData msgbuf;
! 						const char *psdisp;
! 						int			displen;
! 
! 						initStringInfo(&msgbuf);
! 
! 						psdisp = get_ps_display(&displen);
! 						appendBinaryStringInfo(&msgbuf, psdisp, displen);
! 						appendCSVLiteral(&buf, msgbuf.data);
! 
! 						pfree(msgbuf.data);
! 					}
! 					if (curr_field != num_fields) appendStringInfoChar(&buf, ',');
! 				}
! 				break;
  
! 			case CSVLOG_SESSION_START_TIME:
! 				{
! 					/* session start timestamp */
! 					if (formatted_start_time[0] == '\0')
! 						setup_formatted_start_time();
! 					appendStringInfoString(&buf, formatted_start_time);
! 					if (curr_field != num_fields) appendStringInfoChar(&buf, ',');
! 				}
! 				break;
  
! 			case CSVLOG_VIRTUAL_TRANSACTION_ID:
! 				{
! 					/* Virtual transaction id */
! 					/* keep VXID format in sync with lockfuncs.c */
! 					if (MyProc != NULL && MyProc->backendId != InvalidBackendId)
! 						appendStringInfo(&buf, "%d/%u", MyProc->backendId, MyProc->lxid);
! 					if (curr_field != num_fields) appendStringInfoChar(&buf, ',');
! 				}
! 				break;
  
! 			case CSVLOG_TRANSACTION_ID:
! 				/* Transaction id */
! 				appendStringInfo(&buf, "%u", GetTopTransactionIdIfAny());
! 				if (curr_field != num_fields) appendStringInfoChar(&buf, ',');
! 				break;
  
! 			case CSVLOG_ERROR_SEVERITY:
! 				/* Error severity */
! 				appendStringInfoString(&buf, error_severity(edata->elevel));
! 				if (curr_field != num_fields) appendStringInfoChar(&buf, ',');
! 				break;
  
! 			case CSVLOG_SQL_STATE_CODE:
! 				/* SQL state code */
! 				appendStringInfoString(&buf, unpack_sql_state(edata->sqlerrcode));
! 				if (curr_field != num_fields) appendStringInfoChar(&buf, ',');
! 				break;
  
! 			case CSVLOG_MESSAGE:
! 				/* errmessage */
! 				appendCSVLiteral(&buf, edata->message);
! 				if (curr_field != num_fields) appendStringInfoChar(&buf, ',');
! 				break;
  
! 			case CSVLOG_DETAIL:
! 				{
! 					/* errdetail or errdetail_log */
! 					if (edata->detail_log)
! 						appendCSVLiteral(&buf, edata->detail_log);
! 					else
! 						appendCSVLiteral(&buf, edata->detail);
! 					if (curr_field != num_fields) appendStringInfoChar(&buf, ',');
! 				}
! 				break;
  
! 			case CSVLOG_HINT:
! 				/* errhint */
! 				appendCSVLiteral(&buf, edata->hint);
! 				if (curr_field != num_fields) appendStringInfoChar(&buf, ',');
! 				break;
  
! 			case CSVLOG_INTERNAL_QUERY:
! 				/* internal query */
! 				appendCSVLiteral(&buf, edata->internalquery);
! 				if (curr_field != num_fields) appendStringInfoChar(&buf, ',');
! 				break;
  
! 			case CSVLOG_INTERNAL_QUERY_POS:
! 				{
! 					/* if printed internal query, print internal pos too */
! 					if (edata->internalpos > 0 && edata->internalquery != NULL)
! 						appendStringInfo(&buf, "%d", edata->internalpos);
! 					if (curr_field != num_fields) appendStringInfoChar(&buf, ',');
! 				}
! 				break;
  
! 			case CSVLOG_CONTEXT:
! 				/* errcontext */
! 				appendCSVLiteral(&buf, edata->context);
! 				if (curr_field != num_fields) appendStringInfoChar(&buf, ',');
! 				break;
  
! 			case CSVLOG_QUERY:
! 				{
! 					/* user query --- only reported if not disabled by the caller */
! 					if (is_log_level_output(edata->elevel, log_min_error_statement) &&
! 						debug_query_string != NULL &&
! 						!edata->hide_stmt)
! 						print_stmt = true;
! 					if (print_stmt)
! 						appendCSVLiteral(&buf, debug_query_string);
! 					if (curr_field != num_fields) appendStringInfoChar(&buf, ',');
! 				}
! 				break;
  
! 			case CSVLOG_QUERY_POS:
! 				{
! 					if (print_stmt && edata->cursorpos > 0)
! 						appendStringInfo(&buf, "%d", edata->cursorpos);
! 					if (curr_field != num_fields) appendStringInfoChar(&buf, ',');
! 				}
! 				break;
  
! 			case CSVLOG_LOCATION:
! 				{
! 					/* file error location */
! 					if (Log_error_verbosity >= PGERROR_VERBOSE)
! 					{
! 						StringInfoData msgbuf;
! 
! 						initStringInfo(&msgbuf);
! 
! 						if (edata->funcname && edata->filename)
! 							appendStringInfo(&msgbuf, "%s, %s:%d",
! 											 edata->funcname, edata->filename,
! 											 edata->lineno);
! 						else if (edata->filename)
! 							appendStringInfo(&msgbuf, "%s:%d",
! 											 edata->filename, edata->lineno);
! 						appendCSVLiteral(&buf, msgbuf.data);
! 						pfree(msgbuf.data);
! 					}
! 					if (curr_field != num_fields) appendStringInfoChar(&buf, ',');
! 				}
! 				break;
! 
! 			case CSVLOG_APPLICATION_NAME:
! 				{
! 					/* application name */
! 					if (application_name)
! 						appendCSVLiteral(&buf, application_name);
! 					if (curr_field != num_fields) appendStringInfoChar(&buf, ',');
! 				}
! 				break;
! 		}
! 	}
  
  	appendStringInfoChar(&buf, '\n');
  
***************
*** 2139,2144 **** write_csvlog(ErrorData *edata)
--- 2442,2449 ----
  		write_pipe_chunks(buf.data, buf.len, LOG_DESTINATION_CSVLOG);
  
  	pfree(buf.data);
+ 
+ 	return;
  }
  
  /*
*** a/src/backend/utils/misc/guc.c
--- b/src/backend/utils/misc/guc.c
***************
*** 63,68 ****
--- 63,69 ----
  #include "tsearch/ts_cache.h"
  #include "utils/builtins.h"
  #include "utils/bytea.h"
+ #include "utils/elog.h"
  #include "utils/guc_tables.h"
  #include "utils/memutils.h"
  #include "utils/pg_locale.h"
***************
*** 190,195 **** static char *config_enum_get_options(struct config_enum * record,
--- 191,199 ----
  						const char *prefix, const char *suffix,
  						const char *separator);
  
+ /* Needs to be defined here because elog.h can't #include guc.h */
+ extern const char *assign_log_csv_fields(const char *newval,
+                 bool doit, GucSource source);
  
  /*
   * Options for enum values defined in this module.
***************
*** 2287,2292 **** static struct config_string ConfigureNamesString[] =
--- 2291,2307 ----
  	},
  
  	{
+ 		{"log_csv_fields", PGC_POSTMASTER, LOGGING_WHAT,
+ 			gettext_noop("Controls fields logged to CSV logfiles."),
+ 			gettext_noop("If blank, the default set of fields is used."),
+ 			GUC_LIST_INPUT
+ 		},
+ 		&Log_csv_fields,
+ 		"log_time, user_name, database_name, process_id, connection_from, session_id, session_line_num, command_tag, session_start_time, virtual_transaction_id, transaction_id, error_severity, sql_state_code, message, detail, hint, internal_query, internal_query_pos, context, query, query_pos, location, application_name",
+ 		assign_log_csv_fields, NULL
+ 	},
+ 
+ 	{
  		{"log_timezone", PGC_SIGHUP, LOGGING_WHAT,
  			gettext_noop("Sets the time zone to use in log messages."),
  			NULL
***************
*** 3436,3441 **** InitializeGUCOptions(void)
--- 3451,3462 ----
  	pg_timezone_pre_initialize();
  
  	/*
+ 	 * Ditto for log_csv_fields, have to set it to something before we get
+ 	 * too far along.
+ 	 */
+ 	build_default_csvlog_list();
+ 
+ 	/*
  	 * Build sorted array of all GUC variables.
  	 */
  	build_guc_variables();
*** a/src/backend/utils/misc/postgresql.conf.sample
--- b/src/backend/utils/misc/postgresql.conf.sample
***************
*** 377,382 ****
--- 377,386 ----
  					#        processes
  					#   %% = '%'
  					# e.g. '<%u%%%d> '
+ 
+ # fields to include in the CSV log output
+ #log_csv_fields = 'log_time, user_name, database_name, process_id, connection_from, session_id, session_line_num, command_tag, session_start_time, virtual_transaction_id, transaction_id, error_severity, sql_state_code, message, detail, hint, internal_query, internal_query_pos, context, query, query_pos, location, application_name'
+ 
  #log_lock_waits = off			# log lock waits >= deadlock_timeout
  #log_statement = 'none'			# none, ddl, mod, all
  #log_temp_files = -1			# log temporary files equal or larger
*** a/src/include/utils/elog.h
--- b/src/include/utils/elog.h
***************
*** 330,337 **** typedef enum
--- 330,366 ----
  
  extern int	Log_error_verbosity;
  extern char *Log_line_prefix;
+ extern char *Log_csv_fields;
  extern int	Log_destination;
  
+ typedef enum LogCSVFields
+ {
+ 	CSVLOG_LOG_TIME,
+ 	CSVLOG_USER_NAME,
+ 	CSVLOG_ROLE_NAME,
+ 	CSVLOG_DATABASE_NAME,
+ 	CSVLOG_PROCESS_ID,
+ 	CSVLOG_CONNECTION_FROM,
+ 	CSVLOG_SESSION_ID,
+ 	CSVLOG_SESSION_LINE_NUM,
+ 	CSVLOG_COMMAND_TAG,
+ 	CSVLOG_SESSION_START_TIME,
+ 	CSVLOG_VIRTUAL_TRANSACTION_ID,
+ 	CSVLOG_TRANSACTION_ID,
+ 	CSVLOG_ERROR_SEVERITY,
+ 	CSVLOG_SQL_STATE_CODE,
+ 	CSVLOG_MESSAGE,
+ 	CSVLOG_DETAIL,
+ 	CSVLOG_HINT,
+ 	CSVLOG_INTERNAL_QUERY,
+ 	CSVLOG_INTERNAL_QUERY_POS,
+ 	CSVLOG_CONTEXT,
+ 	CSVLOG_QUERY,
+ 	CSVLOG_QUERY_POS,
+ 	CSVLOG_LOCATION,
+ 	CSVLOG_APPLICATION_NAME
+ } LogCSVFields;
+ 
  /* Log destination bitmap */
  #define LOG_DESTINATION_STDERR	 1
  #define LOG_DESTINATION_SYSLOG	 2
***************
*** 343,348 **** extern void DebugFileOpen(void);
--- 372,382 ----
  extern char *unpack_sql_state(int sql_state);
  extern bool in_error_recursion_trouble(void);
  
+ /* Used by guc.c to set up the default set of
+  * csv fields to log
+  */
+ extern void build_default_csvlog_list(void);
+ 
  #ifdef HAVE_SYSLOG
  extern void set_syslog_parameters(const char *ident, int facility);
  #endif
*** a/src/tools/pgindent/typedefs.list
--- b/src/tools/pgindent/typedefs.list
***************
*** 854,859 **** LockTagType
--- 854,860 ----
  LockTupleMode
  LockingClause
  LogStmtLevel
+ LogCSVFields
  LogicalTape
  LogicalTapeSet
  MAGIC

*** a/doc/src/sgml/config.sgml
--- b/doc/src/sgml/config.sgml
***************
*** 3519,3525 **** local0.*    /var/log/postgresql
              </row>
              <row>
               <entry><literal>%u</literal></entry>
!              <entry>User name</entry>
               <entry>yes</entry>
              </row>
              <row>
--- 3519,3538 ----
              </row>
              <row>
               <entry><literal>%u</literal></entry>
!              <entry>Session user name, typically the user name which was used
!              to authenticate to <productname>PostgreSQL</productname> with,
!              but can be changed by a superuser, see <command>SET SESSION
!              AUTHORIZATION</></entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>%U</literal></entry>
!              <entry>Current role name, when set with <command>SET ROLE</>;
!              the current role identifier is relevant for permission checking;
!              Returns 'none' if the current role matches the session user.
!              Note: Log messages from inside <literal>SECURITY DEFINER</>
!              functions will show the calling role, not the effective role
!              inside the <literal>SECURITY DEFINER</> function</entry>
               <entry>yes</entry>
              </row>
              <row>
***************
*** 3636,3641 **** FROM pg_stat_activity;
--- 3649,3677 ----
        </listitem>
       </varlistentry>
  
+      <varlistentry id="guc-log-csv-fields" xreflabel="log_csv_fields">
+       <term><varname>log_csv_fields</varname> (<type>string</type>)</term>
+       <indexterm>
+        <primary><varname>log_csv_fields</> configuration parameter</primary>
+       </indexterm>
+       <listitem>
+        <para>
+         Controls the set and order of the fields which are written out in
+         the CSV-format log file.
+ 
+         The default is: log_time, user_name, database_name, process_id,
+         connection_from, session_id, session_line_num, command_tag,
+         session_start_time, virtual_transaction_id, transaction_id,
+         error_severity, sql_state_code, message, detail, hint,
+         internal_query, internal_query_pos, context, query, query_pos,
+         location, application_name
+ 
+         For details on what these fields are, refer to the log_line_prefix
+         and CSV logging documentation.
+        </para>
+       </listitem>
+      </varlistentry>
+ 
       <varlistentry id="guc-log-lock-waits" xreflabel="log_lock_waits">
        <term><varname>log_lock_waits</varname> (<type>boolean</type>)</term>
        <indexterm>
***************
*** 3743,3776 **** FROM pg_stat_activity;
          Including <literal>csvlog</> in the <varname>log_destination</> list
          provides a convenient way to import log files into a database table.
          This option emits log lines in comma-separated-values
!         (<acronym>CSV</>) format,
!         with these columns:
!         timestamp with milliseconds,
!         user name,
!         database name,
!         process ID,
!         client host:port number,
!         session ID,
!         per-session line number,
!         command tag,
!         session start time,
!         virtual transaction ID,
!         regular transaction ID,
!         error severity,
!         SQLSTATE code,
!         error message,
!         error message detail,
!         hint,
!         internal query that led to the error (if any),
!         character count of the error position therein,
!         error context,
!         user query that led to the error (if any and enabled by
!         <varname>log_min_error_statement</>),
!         character count of the error position therein,
!         location of the error in the PostgreSQL source code
!         (if <varname>log_error_verbosity</> is set to <literal>verbose</>),
!         and application name.
!         Here is a sample table definition for storing CSV-format log output:
  
  <programlisting>
  CREATE TABLE postgres_log
--- 3779,3931 ----
          Including <literal>csvlog</> in the <varname>log_destination</> list
          provides a convenient way to import log files into a database table.
          This option emits log lines in comma-separated-values
!         (<acronym>CSV</>) format.  The following table defines the fields
! 		which can be included in the CSV output, their meanings, and if they
! 		are included in the default CSV layout (the default ordering matches
! 		the order of this table).
! 
!          <informaltable>
!           <tgroup cols="3">
!            <thead>
!             <row>
!              <entry>CSV Field Name</entry>
!              <entry>Definition</entry>
!              <entry>Included by Default</entry>
!              </row>
!             </thead>
!            <tbody>
!             <row>
!              <entry><literal>log_time</literal></entry>
!              <entry>timestamp with milliseconds</entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>user_name</literal></entry>
!              <entry>session user name</entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>role_name</literal></entry>
!              <entry>current role name</entry>
!              <entry>no</entry>
!             </row>
!             <row>
!              <entry><literal>database_name</literal></entry>
!              <entry>name of database connected to</entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>process_id</literal></entry>
!              <entry>process ID of the backend PG process</entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>connection_from</literal></entry>
!              <entry>client host/IP and port number</entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>session_id</literal></entry>
!              <entry>ID of the session</entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>session_line_number</literal></entry>
!              <entry>per-session line number</entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>command_tag</literal></entry>
!              <entry>Command tag of the logged command</entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>session_start_time</literal></entry>
!              <entry>Start time of the current session</entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>virtual_transaction_id</literal></entry>
!              <entry>Virtual Transaction ID</entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>transaction_id</literal></entry>
!              <entry>Regular Transaction ID</entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>error_severity</literal></entry>
!              <entry>Error severity code of the log message</entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>sql_state_code</literal></entry>
!              <entry>SQLSTATE code of the command being logged</entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>message</literal></entry>
!              <entry>Error message</entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>detail</literal></entry>
!              <entry>Error message detail</entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>hint</literal></entry>
!              <entry>Error message hint</entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>internal_query</literal></entry>
!              <entry>internal query that led to the error (if any)</entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>internal_query_pos</literal></entry>
!              <entry>character count of the error position of the internal query</entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>context</literal></entry>
!              <entry>error context</entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>query</literal></entry>
!              <entry>user query that led to the error (if any and enabled by <varname>log_min_error_statement</varname>)</entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>query_pos</literal></entry>
!              <entry>character count of the error position of the user query</entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>location</literal></entry>
!              <entry>location of the error in the PostgreSQL source code (if <varname>log_error_verbosity</varname> is set to <literal>verbose</literal>)</entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>application_name</literal></entry>
!              <entry>Name of the connecting application, if provided by the application</entry>
!              <entry>yes</entry>
!             </row>
!            </tbody>
!           </tgroup>
!          </informaltable>
! 
!         The set of columns to be included, and their order, in the CSV
!         output can be controlled using the <varname>log_csv_fields</varname> option.
! 
!         For additional details on the definition of the above columns, refer
!         to the documentation for <varname>log_line_prefix</varname>.
! 
!         Here is a sample table definition for storing the default CSV-format
!         log output:
  
  <programlisting>
  CREATE TABLE postgres_log
*** a/src/backend/commands/variable.c
--- b/src/backend/commands/variable.c
***************
*** 809,814 **** assign_session_authorization(const char *value, bool doit, GucSource source)
--- 809,819 ----
  	return result;
  }
  
+ /*
+  * function to return the stored session username, needed because we
+  * can't do catalog lookups when possibly being called after an error,
+  * eg: from elog.c or part of GUC handling.
+  */
  const char *
  show_session_authorization(void)
  {
***************
*** 934,939 **** assign_role(const char *value, bool doit, GucSource source)
--- 939,949 ----
  	return result;
  }
  
+ /*
+  * function to return the stored role username, needed because we
+  * can't do catalog lookups when possibly being called after an error,
+  * eg: from elog.c or part of GUC handling.
+  */
  const char *
  show_role(void)
  {
*** a/src/backend/utils/error/elog.c
--- b/src/backend/utils/error/elog.c
***************
*** 3,8 ****
--- 3,17 ----
   * elog.c
   *	  error logging and reporting
   *
+  * A few comments about situations where error processing is called:
+  *
+  * We need to be cautious of both a performance hit when logging, since
+  * log messages can be generated at a huge rate if every command is being
+  * logged and we also need to watch out for what can happen when we are
+  * trying to log from an aborted transaction.  Specifically, attempting to
+  * do SysCache lookups and possibly use other usually available backend
+  * systems will fail badly when logging from an aborted transaction.
+  *
   * Some notes about recursion and errors during error processing:
   *
   * We need to be robust about recursive-error scenarios --- for example,
***************
*** 59,73 ****
--- 68,85 ----
  
  #include "access/transam.h"
  #include "access/xact.h"
+ #include "commands/variable.h"
  #include "libpq/libpq.h"
  #include "libpq/pqformat.h"
  #include "mb/pg_wchar.h"
  #include "miscadmin.h"
+ #include "nodes/pg_list.h"
  #include "postmaster/postmaster.h"
  #include "postmaster/syslogger.h"
  #include "storage/ipc.h"
  #include "storage/proc.h"
  #include "tcop/tcopprot.h"
+ #include "utils/builtins.h"
  #include "utils/guc.h"
  #include "utils/memutils.h"
  #include "utils/ps_status.h"
***************
*** 93,98 **** extern bool redirection_done;
--- 105,113 ----
  int			Log_error_verbosity = PGERROR_VERBOSE;
  char	   *Log_line_prefix = NULL;		/* format for extra log line info */
  int			Log_destination = LOG_DESTINATION_STDERR;
+ char	   *Log_csv_fields = NULL;
+ 
+ static List *csv_log_fields = NIL;
  
  #ifdef HAVE_SYSLOG
  
***************
*** 161,166 **** static void write_csvlog(ErrorData *edata);
--- 176,186 ----
  static void setup_formatted_log_time(void);
  static void setup_formatted_start_time(void);
  
+ /* extern'd and used from guc.c... */
+ const char *
+ assign_log_csv_fields(const char *newval, bool doit, GucSource source);
+ 
+ 
  
  /*
   * in_error_recursion_trouble --- are we at risk of infinite error recursion?
***************
*** 1817,1831 **** log_line_prefix(StringInfo buf, ErrorData *edata)
  				}
  				break;
  			case 'u':
- 				if (MyProcPort)
  				{
! 					const char *username = MyProcPort->user_name;
! 
! 					if (username == NULL || *username == '\0')
! 						username = _("[unknown]");
! 					appendStringInfoString(buf, username);
  				}
  				break;
  			case 'd':
  				if (MyProcPort)
  				{
--- 1837,1860 ----
  				}
  				break;
  			case 'u':
  				{
! 				const char *session_auth = show_session_authorization();
! 				if (*session_auth != '\0')
! 					appendStringInfoString(buf, session_auth);
! 				else
! 					if (MyProcPort)
! 					{
! 						const char *username = MyProcPort->user_name;
! 
! 						if (username == NULL || *username == '\0')
! 							username = _("[unknown]");
! 						appendStringInfoString(buf, username);
! 					}
  				}
  				break;
+ 			case 'U':
+ 				appendStringInfoString(buf, show_role());
+ 				break;
  			case 'd':
  				if (MyProcPort)
  				{
***************
*** 1921,1926 **** log_line_prefix(StringInfo buf, ErrorData *edata)
--- 1950,2112 ----
  }
  
  /*
+  * Build up the default set of CSV fields to output, in case we need it before
+  * GUC processing is done.
+  *
+  * This is more of a 'safety valve' than anything else,
+  * since GUC processing really should happen before we do any error logging.
+  * We might even want to change this eventually to just not log CSV format logs
+  * if this ever happens, to avoid a discrepency in the CSV log file which would
+  * make it difficult to load into PG.
+  */
+ void
+ build_default_csvlog_list(void)
+ {
+ 	List		*new_csv_fields = NIL;
+ 	MemoryContext oldcontext;
+ 
+ 	oldcontext = MemoryContextSwitchTo(TopMemoryContext);
+ 
+ 	new_csv_fields = lappend_int(new_csv_fields,CSVLOG_LOG_TIME);
+ 	new_csv_fields = lappend_int(new_csv_fields,CSVLOG_USER_NAME);
+ 	new_csv_fields = lappend_int(new_csv_fields,CSVLOG_DATABASE_NAME);
+ 	new_csv_fields = lappend_int(new_csv_fields,CSVLOG_PROCESS_ID);
+ 	new_csv_fields = lappend_int(new_csv_fields,CSVLOG_CONNECTION_FROM);
+ 	new_csv_fields = lappend_int(new_csv_fields,CSVLOG_SESSION_ID);
+ 	new_csv_fields = lappend_int(new_csv_fields,CSVLOG_SESSION_LINE_NUM);
+ 	new_csv_fields = lappend_int(new_csv_fields,CSVLOG_COMMAND_TAG);
+ 	new_csv_fields = lappend_int(new_csv_fields,CSVLOG_SESSION_START_TIME);
+ 	new_csv_fields = lappend_int(new_csv_fields,CSVLOG_VIRTUAL_TRANSACTION_ID);
+ 	new_csv_fields = lappend_int(new_csv_fields,CSVLOG_TRANSACTION_ID);
+ 	new_csv_fields = lappend_int(new_csv_fields,CSVLOG_ERROR_SEVERITY);
+ 	new_csv_fields = lappend_int(new_csv_fields,CSVLOG_SQL_STATE_CODE);
+ 	new_csv_fields = lappend_int(new_csv_fields,CSVLOG_MESSAGE);
+ 	new_csv_fields = lappend_int(new_csv_fields,CSVLOG_DETAIL);
+ 	new_csv_fields = lappend_int(new_csv_fields,CSVLOG_HINT);
+ 	new_csv_fields = lappend_int(new_csv_fields,CSVLOG_INTERNAL_QUERY);
+ 	new_csv_fields = lappend_int(new_csv_fields,CSVLOG_INTERNAL_QUERY_POS);
+ 	new_csv_fields = lappend_int(new_csv_fields,CSVLOG_CONTEXT);
+ 	new_csv_fields = lappend_int(new_csv_fields,CSVLOG_QUERY);
+ 	new_csv_fields = lappend_int(new_csv_fields,CSVLOG_QUERY_POS);
+ 	new_csv_fields = lappend_int(new_csv_fields,CSVLOG_LOCATION);
+ 	new_csv_fields = lappend_int(new_csv_fields,CSVLOG_APPLICATION_NAME);
+ 
+ 	/* put new list in place */
+ 	csv_log_fields = new_csv_fields;
+ 
+ 	MemoryContextSwitchTo(oldcontext);
+ 
+ 	return;
+ }
+ 
+ 
+ /*
+  * Process the list of fields to be sent to the CSV log file
+  */
+ const char *
+ assign_log_csv_fields(const char *newval, bool doit, GucSource source)
+ {
+ 	/* Verify the list is valid */
+ 	List		*new_csv_fields = NIL;
+ 	List		*column_list = NIL;
+ 	ListCell	*l;
+ 	char		*rawstring;
+ 	MemoryContext oldcontext;
+ 
+ 	/* Need a modifyable version to pass to SplitIdentifierString */
+ 	rawstring = pstrdup(newval);
+ 
+     /* Parse string into list of identifiers */
+     if (!SplitIdentifierString(rawstring, ',', &column_list))
+ 	{
+ 		list_free(column_list);
+ 		return NULL;
+ 	}
+ 
+ 	/*
+ 	 * We need the allocations done for the csv_log_fields list to
+ 	 * be preserved, so allocate them in TopMemoryContext.
+ 	 */
+ 	oldcontext = MemoryContextSwitchTo(TopMemoryContext);
+ 
+ 	/*
+ 	 * Loop through all of the fields provided by the user and build
+ 	 * up our new_csv_fields list which will be processed by write_csvlog
+ 	 */
+ 	foreach(l, column_list)
+ 	{
+ 		if (pg_strcasecmp(lfirst(l),"log_time") == 0)
+ 			new_csv_fields = lappend_int(new_csv_fields,CSVLOG_LOG_TIME);
+ 		else if (pg_strcasecmp(lfirst(l),"user_name") == 0)
+ 			new_csv_fields = lappend_int(new_csv_fields,CSVLOG_USER_NAME);
+ 		else if (pg_strcasecmp(lfirst(l),"role_name") == 0)
+ 			new_csv_fields = lappend_int(new_csv_fields,CSVLOG_ROLE_NAME);
+ 		else if (pg_strcasecmp(lfirst(l),"database_name") == 0)
+ 			new_csv_fields = lappend_int(new_csv_fields,CSVLOG_DATABASE_NAME);
+ 		else if (pg_strcasecmp(lfirst(l),"process_id") == 0)
+ 			new_csv_fields = lappend_int(new_csv_fields,CSVLOG_PROCESS_ID);
+ 		else if (pg_strcasecmp(lfirst(l),"connection_from") == 0)
+ 			new_csv_fields = lappend_int(new_csv_fields,CSVLOG_CONNECTION_FROM);
+ 		else if (pg_strcasecmp(lfirst(l),"session_id") == 0)
+ 			new_csv_fields = lappend_int(new_csv_fields,CSVLOG_SESSION_ID);
+ 		else if (pg_strcasecmp(lfirst(l),"session_line_num") == 0)
+ 			new_csv_fields = lappend_int(new_csv_fields,CSVLOG_SESSION_LINE_NUM);
+ 		else if (pg_strcasecmp(lfirst(l),"command_tag") == 0)
+ 			new_csv_fields = lappend_int(new_csv_fields,CSVLOG_COMMAND_TAG);
+ 		else if (pg_strcasecmp(lfirst(l),"session_start_time") == 0)
+ 			new_csv_fields = lappend_int(new_csv_fields,CSVLOG_SESSION_START_TIME);
+ 		else if (pg_strcasecmp(lfirst(l),"virtual_transaction_id") == 0)
+ 			new_csv_fields = lappend_int(new_csv_fields,CSVLOG_VIRTUAL_TRANSACTION_ID);
+ 		else if (pg_strcasecmp(lfirst(l),"transaction_id") == 0)
+ 			new_csv_fields = lappend_int(new_csv_fields,CSVLOG_TRANSACTION_ID);
+ 		else if (pg_strcasecmp(lfirst(l),"error_severity") == 0)
+ 			new_csv_fields = lappend_int(new_csv_fields,CSVLOG_ERROR_SEVERITY);
+ 		else if (pg_strcasecmp(lfirst(l),"sql_state_code") == 0)
+ 			new_csv_fields = lappend_int(new_csv_fields,CSVLOG_SQL_STATE_CODE);
+ 		else if (pg_strcasecmp(lfirst(l),"message") == 0)
+ 			new_csv_fields = lappend_int(new_csv_fields,CSVLOG_MESSAGE);
+ 		else if (pg_strcasecmp(lfirst(l),"detail") == 0)
+ 			new_csv_fields = lappend_int(new_csv_fields,CSVLOG_DETAIL);
+ 		else if (pg_strcasecmp(lfirst(l),"hint") == 0)
+ 			new_csv_fields = lappend_int(new_csv_fields,CSVLOG_HINT);
+ 		else if (pg_strcasecmp(lfirst(l),"internal_query") == 0)
+ 			new_csv_fields = lappend_int(new_csv_fields,CSVLOG_INTERNAL_QUERY);
+ 		else if (pg_strcasecmp(lfirst(l),"internal_query_pos") == 0)
+ 			new_csv_fields = lappend_int(new_csv_fields,CSVLOG_INTERNAL_QUERY_POS);
+ 		else if (pg_strcasecmp(lfirst(l),"context") == 0)
+ 			new_csv_fields = lappend_int(new_csv_fields,CSVLOG_CONTEXT);
+ 		else if (pg_strcasecmp(lfirst(l),"query") == 0)
+ 			new_csv_fields = lappend_int(new_csv_fields,CSVLOG_QUERY);
+ 		else if (pg_strcasecmp(lfirst(l),"query_pos") == 0)
+ 			new_csv_fields = lappend_int(new_csv_fields,CSVLOG_QUERY_POS);
+ 		else if (pg_strcasecmp(lfirst(l),"location") == 0)
+ 			new_csv_fields = lappend_int(new_csv_fields,CSVLOG_LOCATION);
+ 		else if (pg_strcasecmp(lfirst(l),"application_name") == 0)
+ 			new_csv_fields = lappend_int(new_csv_fields,CSVLOG_APPLICATION_NAME);
+ 		else
+ 		{
+ 			/* handle error, might need to do better than this */
+ 			return NULL;
+ 		}
+ 	}
+ 
+ 	if (doit)
+ 	{
+ 		/* put new list in place */
+ 		List *old_list = csv_log_fields;
+ 
+ 		csv_log_fields = new_csv_fields;
+ 
+ 		list_free(old_list);
+ 	}
+ 
+ 	/* Switch back to the calling context */
+ 	MemoryContextSwitchTo(oldcontext);
+ 
+ 	return newval;
+ }
+ 
+ /*
   * append a CSV'd version of a string to a StringInfo
   * We use the PostgreSQL defaults for CSV, i.e. quote = escape = '"'
   * If it's NULL, append nothing.
***************
*** 1946,1957 **** appendCSVLiteral(StringInfo buf, const char *data)
  }
  
  /*
!  * Constructs the error message, depending on the Errordata it gets, in a CSV
!  * format which is described in doc/src/sgml/config.sgml.
   */
  static void
  write_csvlog(ErrorData *edata)
  {
  	StringInfoData buf;
  	bool		print_stmt = false;
  
--- 2132,2145 ----
  }
  
  /*
!  * Constructs the error message, depending on the Errordata it gets, in the CSV
!  * format requested by the user, based on the log_csv_fields GUC.
   */
  static void
  write_csvlog(ErrorData *edata)
  {
+ 	int			num_fields;
+ 	int			curr_field = 0;
  	StringInfoData buf;
  	bool		print_stmt = false;
  
***************
*** 1961,1966 **** write_csvlog(ErrorData *edata)
--- 2149,2158 ----
  	/* has counter been reset in current process? */
  	static int	log_my_pid = 0;
  
+ 	ListCell	*l;
+ 
+ 	const char *session_auth = show_session_authorization();
+ 
  	/*
  	 * This is one of the few places where we'd rather not inherit a static
  	 * variable's value from the postmaster.  But since we will, reset it when
***************
*** 1977,2134 **** write_csvlog(ErrorData *edata)
  	initStringInfo(&buf);
  
  	/*
! 	 * timestamp with milliseconds
! 	 *
! 	 * Check if the timestamp is already calculated for the syslog message,
! 	 * and use it if so.  Otherwise, get the current timestamp.  This is done
! 	 * to put same timestamp in both syslog and csvlog messages.
  	 */
! 	if (formatted_log_time[0] == '\0')
! 		setup_formatted_log_time();
  
! 	appendStringInfoString(&buf, formatted_log_time);
! 	appendStringInfoChar(&buf, ',');
  
! 	/* username */
! 	if (MyProcPort)
! 		appendCSVLiteral(&buf, MyProcPort->user_name);
! 	appendStringInfoChar(&buf, ',');
  
! 	/* database name */
! 	if (MyProcPort)
! 		appendCSVLiteral(&buf, MyProcPort->database_name);
! 	appendStringInfoChar(&buf, ',');
  
! 	/* Process id  */
! 	if (MyProcPid != 0)
! 		appendStringInfo(&buf, "%d", MyProcPid);
! 	appendStringInfoChar(&buf, ',');
  
! 	/* Remote host and port */
! 	if (MyProcPort && MyProcPort->remote_host)
! 	{
! 		appendStringInfoChar(&buf, '"');
! 		appendStringInfoString(&buf, MyProcPort->remote_host);
! 		if (MyProcPort->remote_port && MyProcPort->remote_port[0] != '\0')
! 		{
! 			appendStringInfoChar(&buf, ':');
! 			appendStringInfoString(&buf, MyProcPort->remote_port);
! 		}
! 		appendStringInfoChar(&buf, '"');
! 	}
! 	appendStringInfoChar(&buf, ',');
  
! 	/* session id */
! 	appendStringInfo(&buf, "%lx.%x", (long) MyStartTime, MyProcPid);
! 	appendStringInfoChar(&buf, ',');
  
! 	/* Line number */
! 	appendStringInfo(&buf, "%ld", log_line_number);
! 	appendStringInfoChar(&buf, ',');
  
! 	/* PS display */
! 	if (MyProcPort)
! 	{
! 		StringInfoData msgbuf;
! 		const char *psdisp;
! 		int			displen;
  
! 		initStringInfo(&msgbuf);
  
! 		psdisp = get_ps_display(&displen);
! 		appendBinaryStringInfo(&msgbuf, psdisp, displen);
! 		appendCSVLiteral(&buf, msgbuf.data);
  
! 		pfree(msgbuf.data);
! 	}
! 	appendStringInfoChar(&buf, ',');
  
! 	/* session start timestamp */
! 	if (formatted_start_time[0] == '\0')
! 		setup_formatted_start_time();
! 	appendStringInfoString(&buf, formatted_start_time);
! 	appendStringInfoChar(&buf, ',');
  
! 	/* Virtual transaction id */
! 	/* keep VXID format in sync with lockfuncs.c */
! 	if (MyProc != NULL && MyProc->backendId != InvalidBackendId)
! 		appendStringInfo(&buf, "%d/%u", MyProc->backendId, MyProc->lxid);
! 	appendStringInfoChar(&buf, ',');
  
! 	/* Transaction id */
! 	appendStringInfo(&buf, "%u", GetTopTransactionIdIfAny());
! 	appendStringInfoChar(&buf, ',');
  
! 	/* Error severity */
! 	appendStringInfoString(&buf, error_severity(edata->elevel));
! 	appendStringInfoChar(&buf, ',');
  
! 	/* SQL state code */
! 	appendStringInfoString(&buf, unpack_sql_state(edata->sqlerrcode));
! 	appendStringInfoChar(&buf, ',');
  
! 	/* errmessage */
! 	appendCSVLiteral(&buf, edata->message);
! 	appendStringInfoChar(&buf, ',');
  
! 	/* errdetail or errdetail_log */
! 	if (edata->detail_log)
! 		appendCSVLiteral(&buf, edata->detail_log);
! 	else
! 		appendCSVLiteral(&buf, edata->detail);
! 	appendStringInfoChar(&buf, ',');
  
! 	/* errhint */
! 	appendCSVLiteral(&buf, edata->hint);
! 	appendStringInfoChar(&buf, ',');
  
! 	/* internal query */
! 	appendCSVLiteral(&buf, edata->internalquery);
! 	appendStringInfoChar(&buf, ',');
  
! 	/* if printed internal query, print internal pos too */
! 	if (edata->internalpos > 0 && edata->internalquery != NULL)
! 		appendStringInfo(&buf, "%d", edata->internalpos);
! 	appendStringInfoChar(&buf, ',');
  
! 	/* errcontext */
! 	appendCSVLiteral(&buf, edata->context);
! 	appendStringInfoChar(&buf, ',');
  
! 	/* user query --- only reported if not disabled by the caller */
! 	if (is_log_level_output(edata->elevel, log_min_error_statement) &&
! 		debug_query_string != NULL &&
! 		!edata->hide_stmt)
! 		print_stmt = true;
! 	if (print_stmt)
! 		appendCSVLiteral(&buf, debug_query_string);
! 	appendStringInfoChar(&buf, ',');
! 	if (print_stmt && edata->cursorpos > 0)
! 		appendStringInfo(&buf, "%d", edata->cursorpos);
! 	appendStringInfoChar(&buf, ',');
! 
! 	/* file error location */
! 	if (Log_error_verbosity >= PGERROR_VERBOSE)
! 	{
! 		StringInfoData msgbuf;
! 
! 		initStringInfo(&msgbuf);
! 
! 		if (edata->funcname && edata->filename)
! 			appendStringInfo(&msgbuf, "%s, %s:%d",
! 							 edata->funcname, edata->filename,
! 							 edata->lineno);
! 		else if (edata->filename)
! 			appendStringInfo(&msgbuf, "%s:%d",
! 							 edata->filename, edata->lineno);
! 		appendCSVLiteral(&buf, msgbuf.data);
! 		pfree(msgbuf.data);
! 	}
! 	appendStringInfoChar(&buf, ',');
  
! 	/* application name */
! 	if (application_name)
! 		appendCSVLiteral(&buf, application_name);
  
  	appendStringInfoChar(&buf, '\n');
  
--- 2169,2437 ----
  	initStringInfo(&buf);
  
  	/*
! 	 * Get the number of fields, so we make sure to *not* include a comma
! 	 * after the last field.
  	 */
! 	num_fields = list_length(csv_log_fields);
  
! 	/*
! 	 * Loop through the fields requested by the user, in the order requested, in
! 	 * the log_csv_fields GUC.
! 	 */
! 	foreach(l, csv_log_fields)
! 	{
! 		/* Update which field we are on, needed to check if it's the last field */
! 		curr_field++;
  
! 		switch (lfirst_int(l))
! 		{
! 			case CSVLOG_LOG_TIME:
! 				{
! 					/*
! 					 * timestamp with milliseconds
! 					 *
! 					 * Check if the timestamp is already calculated for the syslog message,
! 					 * and use it if so.  Otherwise, get the current timestamp.  This is done
! 					 * to put same timestamp in both syslog and csvlog messages.
! 					 */
! 					if (formatted_log_time[0] == '\0')
! 						setup_formatted_log_time();
! 
! 					appendStringInfoString(&buf, formatted_log_time);
! 					if (curr_field != num_fields) appendStringInfoChar(&buf, ',');
! 				}
! 				break;
  
! 			case CSVLOG_USER_NAME:
! 				{
! 					/* session username, as done for %u */
! 					if (*session_auth != '\0')
! 						appendCSVLiteral(&buf, session_auth);
! 					else
! 						/* username */
! 						if (MyProcPort)
! 						{
! 							const char *username = MyProcPort->user_name;
! 							if (username == NULL || *username == '\0')
! 								username = _("[unknown]");
! 							appendCSVLiteral(&buf, MyProcPort->user_name);
! 						}
! 					if (curr_field != num_fields) appendStringInfoChar(&buf, ',');
! 				}
! 				break;
  
! 			case CSVLOG_ROLE_NAME:
! 				/* current role, not updated if someone renames it in another
! 				 * session, of course */
! 				appendCSVLiteral(&buf, show_role());
! 				if (curr_field != num_fields) appendStringInfoChar(&buf, ',');
! 				break;
  
! 			case CSVLOG_DATABASE_NAME:
! 				{
! 					/* database name */
! 					if (MyProcPort)
! 						appendCSVLiteral(&buf, MyProcPort->database_name);
! 					if (curr_field != num_fields) appendStringInfoChar(&buf, ',');
! 				}
! 				break;
  
! 			case CSVLOG_PROCESS_ID:
! 				{
! 					/* Process id  */
! 					if (MyProcPid != 0)
! 						appendStringInfo(&buf, "%d", MyProcPid);
! 					if (curr_field != num_fields) appendStringInfoChar(&buf, ',');
! 				}
! 				break;
  
! 			case CSVLOG_CONNECTION_FROM:
! 				{
! 					/* Remote host and port */
! 					if (MyProcPort && MyProcPort->remote_host)
! 					{
! 						appendStringInfoChar(&buf, '"');
! 						appendStringInfoString(&buf, MyProcPort->remote_host);
! 						if (MyProcPort->remote_port && MyProcPort->remote_port[0] != '\0')
! 						{
! 							appendStringInfoChar(&buf, ':');
! 							appendStringInfoString(&buf, MyProcPort->remote_port);
! 						}
! 						appendStringInfoChar(&buf, '"');
! 					}
! 					if (curr_field != num_fields) appendStringInfoChar(&buf, ',');
! 				}
! 				break;
  
! 			case CSVLOG_SESSION_ID:
! 				/* session id */
! 				appendStringInfo(&buf, "%lx.%x", (long) MyStartTime, MyProcPid);
! 				if (curr_field != num_fields) appendStringInfoChar(&buf, ',');
! 				break;
  
! 			case CSVLOG_SESSION_LINE_NUM:
! 				/* Line number */
! 				appendStringInfo(&buf, "%ld", log_line_number);
! 				if (curr_field != num_fields) appendStringInfoChar(&buf, ',');
! 				break;
  
! 			case CSVLOG_COMMAND_TAG:
! 				{
! 					/* PS display */
! 					if (MyProcPort)
! 					{
! 						StringInfoData msgbuf;
! 						const char *psdisp;
! 						int			displen;
! 
! 						initStringInfo(&msgbuf);
! 
! 						psdisp = get_ps_display(&displen);
! 						appendBinaryStringInfo(&msgbuf, psdisp, displen);
! 						appendCSVLiteral(&buf, msgbuf.data);
! 
! 						pfree(msgbuf.data);
! 					}
! 					if (curr_field != num_fields) appendStringInfoChar(&buf, ',');
! 				}
! 				break;
  
! 			case CSVLOG_SESSION_START_TIME:
! 				{
! 					/* session start timestamp */
! 					if (formatted_start_time[0] == '\0')
! 						setup_formatted_start_time();
! 					appendStringInfoString(&buf, formatted_start_time);
! 					if (curr_field != num_fields) appendStringInfoChar(&buf, ',');
! 				}
! 				break;
  
! 			case CSVLOG_VIRTUAL_TRANSACTION_ID:
! 				{
! 					/* Virtual transaction id */
! 					/* keep VXID format in sync with lockfuncs.c */
! 					if (MyProc != NULL && MyProc->backendId != InvalidBackendId)
! 						appendStringInfo(&buf, "%d/%u", MyProc->backendId, MyProc->lxid);
! 					if (curr_field != num_fields) appendStringInfoChar(&buf, ',');
! 				}
! 				break;
  
! 			case CSVLOG_TRANSACTION_ID:
! 				/* Transaction id */
! 				appendStringInfo(&buf, "%u", GetTopTransactionIdIfAny());
! 				if (curr_field != num_fields) appendStringInfoChar(&buf, ',');
! 				break;
  
! 			case CSVLOG_ERROR_SEVERITY:
! 				/* Error severity */
! 				appendStringInfoString(&buf, error_severity(edata->elevel));
! 				if (curr_field != num_fields) appendStringInfoChar(&buf, ',');
! 				break;
  
! 			case CSVLOG_SQL_STATE_CODE:
! 				/* SQL state code */
! 				appendStringInfoString(&buf, unpack_sql_state(edata->sqlerrcode));
! 				if (curr_field != num_fields) appendStringInfoChar(&buf, ',');
! 				break;
  
! 			case CSVLOG_MESSAGE:
! 				/* errmessage */
! 				appendCSVLiteral(&buf, edata->message);
! 				if (curr_field != num_fields) appendStringInfoChar(&buf, ',');
! 				break;
  
! 			case CSVLOG_DETAIL:
! 				{
! 					/* errdetail or errdetail_log */
! 					if (edata->detail_log)
! 						appendCSVLiteral(&buf, edata->detail_log);
! 					else
! 						appendCSVLiteral(&buf, edata->detail);
! 					if (curr_field != num_fields) appendStringInfoChar(&buf, ',');
! 				}
! 				break;
  
! 			case CSVLOG_HINT:
! 				/* errhint */
! 				appendCSVLiteral(&buf, edata->hint);
! 				if (curr_field != num_fields) appendStringInfoChar(&buf, ',');
! 				break;
  
! 			case CSVLOG_INTERNAL_QUERY:
! 				/* internal query */
! 				appendCSVLiteral(&buf, edata->internalquery);
! 				if (curr_field != num_fields) appendStringInfoChar(&buf, ',');
! 				break;
  
! 			case CSVLOG_INTERNAL_QUERY_POS:
! 				{
! 					/* if printed internal query, print internal pos too */
! 					if (edata->internalpos > 0 && edata->internalquery != NULL)
! 						appendStringInfo(&buf, "%d", edata->internalpos);
! 					if (curr_field != num_fields) appendStringInfoChar(&buf, ',');
! 				}
! 				break;
  
! 			case CSVLOG_CONTEXT:
! 				/* errcontext */
! 				appendCSVLiteral(&buf, edata->context);
! 				if (curr_field != num_fields) appendStringInfoChar(&buf, ',');
! 				break;
  
! 			case CSVLOG_QUERY:
! 				{
! 					/* user query --- only reported if not disabled by the caller */
! 					if (is_log_level_output(edata->elevel, log_min_error_statement) &&
! 						debug_query_string != NULL &&
! 						!edata->hide_stmt)
! 						print_stmt = true;
! 					if (print_stmt)
! 						appendCSVLiteral(&buf, debug_query_string);
! 					if (curr_field != num_fields) appendStringInfoChar(&buf, ',');
! 				}
! 				break;
  
! 			case CSVLOG_QUERY_POS:
! 				{
! 					if (print_stmt && edata->cursorpos > 0)
! 						appendStringInfo(&buf, "%d", edata->cursorpos);
! 					if (curr_field != num_fields) appendStringInfoChar(&buf, ',');
! 				}
! 				break;
  
! 			case CSVLOG_LOCATION:
! 				{
! 					/* file error location */
! 					if (Log_error_verbosity >= PGERROR_VERBOSE)
! 					{
! 						StringInfoData msgbuf;
! 
! 						initStringInfo(&msgbuf);
! 
! 						if (edata->funcname && edata->filename)
! 							appendStringInfo(&msgbuf, "%s, %s:%d",
! 											 edata->funcname, edata->filename,
! 											 edata->lineno);
! 						else if (edata->filename)
! 							appendStringInfo(&msgbuf, "%s:%d",
! 											 edata->filename, edata->lineno);
! 						appendCSVLiteral(&buf, msgbuf.data);
! 						pfree(msgbuf.data);
! 					}
! 					if (curr_field != num_fields) appendStringInfoChar(&buf, ',');
! 				}
! 				break;
! 
! 			case CSVLOG_APPLICATION_NAME:
! 				{
! 					/* application name */
! 					if (application_name)
! 						appendCSVLiteral(&buf, application_name);
! 					if (curr_field != num_fields) appendStringInfoChar(&buf, ',');
! 				}
! 				break;
! 		}
! 	}
  
  	appendStringInfoChar(&buf, '\n');
  
***************
*** 2139,2144 **** write_csvlog(ErrorData *edata)
--- 2442,2449 ----
  		write_pipe_chunks(buf.data, buf.len, LOG_DESTINATION_CSVLOG);
  
  	pfree(buf.data);
+ 
+ 	return;
  }
  
  /*
*** a/src/backend/utils/misc/guc.c
--- b/src/backend/utils/misc/guc.c
***************
*** 63,68 ****
--- 63,69 ----
  #include "tsearch/ts_cache.h"
  #include "utils/builtins.h"
  #include "utils/bytea.h"
+ #include "utils/elog.h"
  #include "utils/guc_tables.h"
  #include "utils/memutils.h"
  #include "utils/pg_locale.h"
***************
*** 189,194 **** static char *config_enum_get_options(struct config_enum * record,
--- 190,198 ----
  						const char *prefix, const char *suffix,
  						const char *separator);
  
+ /* Needs to be defined here because elog.h can't #include guc.h */
+ extern const char *assign_log_csv_fields(const char *newval,
+                 bool doit, GucSource source);
  
  /*
   * Options for enum values defined in this module.
***************
*** 2286,2291 **** static struct config_string ConfigureNamesString[] =
--- 2290,2306 ----
  	},
  
  	{
+ 		{"log_csv_fields", PGC_POSTMASTER, LOGGING_WHAT,
+ 			gettext_noop("Controls fields logged to CSV logfiles."),
+ 			gettext_noop("If blank, the default set of fields is used."),
+ 			GUC_LIST_INPUT
+ 		},
+ 		&Log_csv_fields,
+ 		"log_time, user_name, database_name, process_id, connection_from, session_id, session_line_num, command_tag, session_start_time, virtual_transaction_id, transaction_id, error_severity, sql_state_code, message, detail, hint, internal_query, internal_query_pos, context, query, query_pos, location, application_name",
+ 		assign_log_csv_fields, NULL
+ 	},
+ 
+ 	{
  		{"log_timezone", PGC_SIGHUP, LOGGING_WHAT,
  			gettext_noop("Sets the time zone to use in log messages."),
  			NULL
***************
*** 3435,3440 **** InitializeGUCOptions(void)
--- 3450,3461 ----
  	pg_timezone_pre_initialize();
  
  	/*
+ 	 * Ditto for log_csv_fields, have to set it to something before we get
+ 	 * too far along.
+ 	 */
+ 	build_default_csvlog_list();
+ 
+ 	/*
  	 * Build sorted array of all GUC variables.
  	 */
  	build_guc_variables();
*** a/src/backend/utils/misc/postgresql.conf.sample
--- b/src/backend/utils/misc/postgresql.conf.sample
***************
*** 377,382 ****
--- 377,386 ----
  					#        processes
  					#   %% = '%'
  					# e.g. '<%u%%%d> '
+ 
+ # fields to include in the CSV log output
+ #log_csv_fields = 'log_time, user_name, database_name, process_id, connection_from, session_id, session_line_num, command_tag, session_start_time, virtual_transaction_id, transaction_id, error_severity, sql_state_code, message, detail, hint, internal_query, internal_query_pos, context, query, query_pos, location, application_name'
+ 
  #log_lock_waits = off			# log lock waits >= deadlock_timeout
  #log_statement = 'none'			# none, ddl, mod, all
  #log_temp_files = -1			# log temporary files equal or larger
*** a/src/include/utils/elog.h
--- b/src/include/utils/elog.h
***************
*** 330,337 **** typedef enum
--- 330,366 ----
  
  extern int	Log_error_verbosity;
  extern char *Log_line_prefix;
+ extern char *Log_csv_fields;
  extern int	Log_destination;
  
+ typedef enum LogCSVFields
+ {
+ 	CSVLOG_LOG_TIME,
+ 	CSVLOG_USER_NAME,
+ 	CSVLOG_ROLE_NAME,
+ 	CSVLOG_DATABASE_NAME,
+ 	CSVLOG_PROCESS_ID,
+ 	CSVLOG_CONNECTION_FROM,
+ 	CSVLOG_SESSION_ID,
+ 	CSVLOG_SESSION_LINE_NUM,
+ 	CSVLOG_COMMAND_TAG,
+ 	CSVLOG_SESSION_START_TIME,
+ 	CSVLOG_VIRTUAL_TRANSACTION_ID,
+ 	CSVLOG_TRANSACTION_ID,
+ 	CSVLOG_ERROR_SEVERITY,
+ 	CSVLOG_SQL_STATE_CODE,
+ 	CSVLOG_MESSAGE,
+ 	CSVLOG_DETAIL,
+ 	CSVLOG_HINT,
+ 	CSVLOG_INTERNAL_QUERY,
+ 	CSVLOG_INTERNAL_QUERY_POS,
+ 	CSVLOG_CONTEXT,
+ 	CSVLOG_QUERY,
+ 	CSVLOG_QUERY_POS,
+ 	CSVLOG_LOCATION,
+ 	CSVLOG_APPLICATION_NAME
+ } LogCSVFields;
+ 
  /* Log destination bitmap */
  #define LOG_DESTINATION_STDERR	 1
  #define LOG_DESTINATION_SYSLOG	 2
***************
*** 343,348 **** extern void DebugFileOpen(void);
--- 372,382 ----
  extern char *unpack_sql_state(int sql_state);
  extern bool in_error_recursion_trouble(void);
  
+ /* Used by guc.c to set up the default set of
+  * csv fields to log
+  */
+ extern void build_default_csvlog_list(void);
+ 
  #ifdef HAVE_SYSLOG
  extern void set_syslog_parameters(const char *ident, int facility);
  #endif
*** a/src/tools/pgindent/typedefs.list
--- b/src/tools/pgindent/typedefs.list
***************
*** 854,859 **** LockTagType
--- 854,860 ----
  LockTupleMode
  LockingClause
  LogStmtLevel
+ LogCSVFields
  LogicalTape
  LogicalTapeSet
  MAGIC

*** a/doc/src/sgml/config.sgml
--- b/doc/src/sgml/config.sgml
***************
*** 3519,3525 **** local0.*    /var/log/postgresql
              </row>
              <row>
               <entry><literal>%u</literal></entry>
!              <entry>User name</entry>
               <entry>yes</entry>
              </row>
              <row>
--- 3519,3538 ----
              </row>
              <row>
               <entry><literal>%u</literal></entry>
!              <entry>Session user name, typically the user name which was used
!              to authenticate to <productname>PostgreSQL</productname> with,
!              but can be changed by a superuser, see <command>SET SESSION
!              AUTHORIZATION</></entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>%U</literal></entry>
!              <entry>Current role name, when set with <command>SET ROLE</>;
!              the current role identifier is relevant for permission checking;
!              Returns 'none' if the current role matches the session user.
!              Note: Log messages from inside <literal>SECURITY DEFINER</>
!              functions will show the calling role, not the effective role
!              inside the <literal>SECURITY DEFINER</> function</entry>
               <entry>yes</entry>
              </row>
              <row>
***************
*** 3636,3641 **** FROM pg_stat_activity;
--- 3649,3677 ----
        </listitem>
       </varlistentry>
  
+      <varlistentry id="guc-csvlog-fields" xreflabel="csvlog_fields">
+       <term><varname>csvlog_fields</varname> (<type>string</type>)</term>
+       <indexterm>
+        <primary><varname>csvlog_fields</> configuration parameter</primary>
+       </indexterm>
+       <listitem>
+        <para>
+         Controls the set and order of the fields which are written out in
+         the CSV-format log file.
+ 
+         The default is: log_time, user_name, database_name, process_id,
+         connection_from, session_id, session_line_num, command_tag,
+         session_start_time, virtual_transaction_id, transaction_id,
+         error_severity, sql_state_code, message, detail, hint,
+         internal_query, internal_query_pos, context, query, query_pos,
+         location, application_name
+ 
+         For details on what these fields are, refer to the log_line_prefix
+         and CSV logging documentation.
+        </para>
+       </listitem>
+      </varlistentry>
+ 
       <varlistentry id="guc-log-lock-waits" xreflabel="log_lock_waits">
        <term><varname>log_lock_waits</varname> (<type>boolean</type>)</term>
        <indexterm>
***************
*** 3743,3776 **** FROM pg_stat_activity;
          Including <literal>csvlog</> in the <varname>log_destination</> list
          provides a convenient way to import log files into a database table.
          This option emits log lines in comma-separated-values
!         (<acronym>CSV</>) format,
!         with these columns:
!         timestamp with milliseconds,
!         user name,
!         database name,
!         process ID,
!         client host:port number,
!         session ID,
!         per-session line number,
!         command tag,
!         session start time,
!         virtual transaction ID,
!         regular transaction ID,
!         error severity,
!         SQLSTATE code,
!         error message,
!         error message detail,
!         hint,
!         internal query that led to the error (if any),
!         character count of the error position therein,
!         error context,
!         user query that led to the error (if any and enabled by
!         <varname>log_min_error_statement</>),
!         character count of the error position therein,
!         location of the error in the PostgreSQL source code
!         (if <varname>log_error_verbosity</> is set to <literal>verbose</>),
!         and application name.
!         Here is a sample table definition for storing CSV-format log output:
  
  <programlisting>
  CREATE TABLE postgres_log
--- 3779,3931 ----
          Including <literal>csvlog</> in the <varname>log_destination</> list
          provides a convenient way to import log files into a database table.
          This option emits log lines in comma-separated-values
!         (<acronym>CSV</>) format.  The following table defines the fields
!         which can be included in the CSV output, their meanings, and if they
!         are included in the default CSV layout (the default ordering matches
!         the order of this table).
! 
!          <informaltable>
!           <tgroup cols="3">
!            <thead>
!             <row>
!              <entry>CSV Field Name</entry>
!              <entry>Definition</entry>
!              <entry>Included by Default</entry>
!              </row>
!             </thead>
!            <tbody>
!             <row>
!              <entry><literal>log_time</literal></entry>
!              <entry>timestamp with milliseconds</entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>user_name</literal></entry>
!              <entry>session user name</entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>role_name</literal></entry>
!              <entry>current role name</entry>
!              <entry>no</entry>
!             </row>
!             <row>
!              <entry><literal>database_name</literal></entry>
!              <entry>name of database connected to</entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>process_id</literal></entry>
!              <entry>process ID of the backend PG process</entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>connection_from</literal></entry>
!              <entry>client host/IP and port number</entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>session_id</literal></entry>
!              <entry>ID of the session</entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>session_line_number</literal></entry>
!              <entry>per-session line number</entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>command_tag</literal></entry>
!              <entry>Command tag of the logged command</entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>session_start_time</literal></entry>
!              <entry>Start time of the current session</entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>virtual_transaction_id</literal></entry>
!              <entry>Virtual Transaction ID</entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>transaction_id</literal></entry>
!              <entry>Regular Transaction ID</entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>error_severity</literal></entry>
!              <entry>Error severity code of the log message</entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>sql_state_code</literal></entry>
!              <entry>SQLSTATE code of the command being logged</entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>message</literal></entry>
!              <entry>Error message</entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>detail</literal></entry>
!              <entry>Error message detail</entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>hint</literal></entry>
!              <entry>Error message hint</entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>internal_query</literal></entry>
!              <entry>internal query that led to the error (if any)</entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>internal_query_pos</literal></entry>
!              <entry>character count of the error position of the internal query</entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>context</literal></entry>
!              <entry>error context</entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>query</literal></entry>
!              <entry>user query that led to the error (if any and enabled by <varname>log_min_error_statement</varname>)</entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>query_pos</literal></entry>
!              <entry>character count of the error position of the user query</entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>location</literal></entry>
!              <entry>location of the error in the PostgreSQL source code (if <varname>log_error_verbosity</varname> is set to <literal>verbose</literal>)</entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>application_name</literal></entry>
!              <entry>Name of the connecting application, if provided by the application</entry>
!              <entry>yes</entry>
!             </row>
!            </tbody>
!           </tgroup>
!          </informaltable>
! 
!         The set of columns to be included, and their order, in the CSV
!         output can be controlled using the <varname>csvlog_fields</varname> option.
! 
!         For additional details on the definition of the above columns, refer
!         to the documentation for <varname>log_line_prefix</varname>.
! 
!         Here is a sample table definition for storing the default CSV-format
!         log output:
  
  <programlisting>
  CREATE TABLE postgres_log
*** a/src/backend/commands/variable.c
--- b/src/backend/commands/variable.c
***************
*** 847,852 **** assign_session_authorization(const char *value, bool doit, GucSource source)
--- 847,857 ----
  	return result;
  }
  
+ /*
+  * function to return the stored session username, needed because we
+  * can't do catalog lookups when possibly being called after an error,
+  * eg: from elog.c or part of GUC handling.
+  */
  const char *
  show_session_authorization(void)
  {
***************
*** 972,977 **** assign_role(const char *value, bool doit, GucSource source)
--- 977,987 ----
  	return result;
  }
  
+ /*
+  * function to return the stored role username, needed because we
+  * can't do catalog lookups when possibly being called after an error,
+  * eg: from elog.c or part of GUC handling.
+  */
  const char *
  show_role(void)
  {
*** a/src/backend/utils/error/elog.c
--- b/src/backend/utils/error/elog.c
***************
*** 3,8 ****
--- 3,17 ----
   * elog.c
   *	  error logging and reporting
   *
+  * A few comments about situations where error processing is called:
+  *
+  * We need to be cautious of both a performance hit when logging, since
+  * log messages can be generated at a huge rate if every command is being
+  * logged and we also need to watch out for what can happen when we are
+  * trying to log from an aborted transaction.  Specifically, attempting to
+  * do SysCache lookups and possibly use other usually available backend
+  * systems will fail badly when logging from an aborted transaction.
+  *
   * Some notes about recursion and errors during error processing:
   *
   * We need to be robust about recursive-error scenarios --- for example,
***************
*** 59,73 ****
--- 68,85 ----
  
  #include "access/transam.h"
  #include "access/xact.h"
+ #include "commands/variable.h"
  #include "libpq/libpq.h"
  #include "libpq/pqformat.h"
  #include "mb/pg_wchar.h"
  #include "miscadmin.h"
+ #include "nodes/pg_list.h"
  #include "postmaster/postmaster.h"
  #include "postmaster/syslogger.h"
  #include "storage/ipc.h"
  #include "storage/proc.h"
  #include "tcop/tcopprot.h"
+ #include "utils/builtins.h"
  #include "utils/guc.h"
  #include "utils/memutils.h"
  #include "utils/ps_status.h"
***************
*** 93,98 **** extern bool redirection_done;
--- 105,113 ----
  int			Log_error_verbosity = PGERROR_VERBOSE;
  char	   *Log_line_prefix = NULL;		/* format for extra log line info */
  int			Log_destination = LOG_DESTINATION_STDERR;
+ char	   *csvlog_fields = NULL;
+ 
+ static List *csvlog_field_list = NIL;
  
  #ifdef HAVE_SYSLOG
  
***************
*** 161,166 **** static void write_csvlog(ErrorData *edata);
--- 176,186 ----
  static void setup_formatted_log_time(void);
  static void setup_formatted_start_time(void);
  
+ /* extern'd and used from guc.c... */
+ const char *
+ assign_csvlog_fields(const char *newval, bool doit, GucSource source);
+ 
+ 
  
  /*
   * in_error_recursion_trouble --- are we at risk of infinite error recursion?
***************
*** 1817,1831 **** log_line_prefix(StringInfo buf, ErrorData *edata)
  				}
  				break;
  			case 'u':
- 				if (MyProcPort)
  				{
! 					const char *username = MyProcPort->user_name;
! 
! 					if (username == NULL || *username == '\0')
! 						username = _("[unknown]");
! 					appendStringInfoString(buf, username);
  				}
  				break;
  			case 'd':
  				if (MyProcPort)
  				{
--- 1837,1860 ----
  				}
  				break;
  			case 'u':
  				{
! 				const char *session_auth = show_session_authorization();
! 				if (*session_auth != '\0')
! 					appendStringInfoString(buf, session_auth);
! 				else
! 					if (MyProcPort)
! 					{
! 						const char *username = MyProcPort->user_name;
! 
! 						if (username == NULL || *username == '\0')
! 							username = _("[unknown]");
! 						appendStringInfoString(buf, username);
! 					}
  				}
  				break;
+ 			case 'U':
+ 				appendStringInfoString(buf, show_role());
+ 				break;
  			case 'd':
  				if (MyProcPort)
  				{
***************
*** 1921,1926 **** log_line_prefix(StringInfo buf, ErrorData *edata)
--- 1950,2112 ----
  }
  
  /*
+  * Build up the default set of CSV fields to output, in case we need it before
+  * GUC processing is done.
+  *
+  * This is more of a 'safety valve' than anything else,
+  * since GUC processing really should happen before we do any error logging.
+  * We might even want to change this eventually to just not log CSV format logs
+  * if this ever happens, to avoid a discrepency in the CSV log file which would
+  * make it difficult to load into PG.
+  */
+ void
+ build_default_csvlog_list(void)
+ {
+ 	List		*new_csv_fields = NIL;
+ 	MemoryContext oldcontext;
+ 
+ 	oldcontext = MemoryContextSwitchTo(TopMemoryContext);
+ 
+ 	new_csv_fields = lappend_int(new_csv_fields,CSVLOG_LOG_TIME);
+ 	new_csv_fields = lappend_int(new_csv_fields,CSVLOG_USER_NAME);
+ 	new_csv_fields = lappend_int(new_csv_fields,CSVLOG_DATABASE_NAME);
+ 	new_csv_fields = lappend_int(new_csv_fields,CSVLOG_PROCESS_ID);
+ 	new_csv_fields = lappend_int(new_csv_fields,CSVLOG_CONNECTION_FROM);
+ 	new_csv_fields = lappend_int(new_csv_fields,CSVLOG_SESSION_ID);
+ 	new_csv_fields = lappend_int(new_csv_fields,CSVLOG_SESSION_LINE_NUM);
+ 	new_csv_fields = lappend_int(new_csv_fields,CSVLOG_COMMAND_TAG);
+ 	new_csv_fields = lappend_int(new_csv_fields,CSVLOG_SESSION_START_TIME);
+ 	new_csv_fields = lappend_int(new_csv_fields,CSVLOG_VIRTUAL_TRANSACTION_ID);
+ 	new_csv_fields = lappend_int(new_csv_fields,CSVLOG_TRANSACTION_ID);
+ 	new_csv_fields = lappend_int(new_csv_fields,CSVLOG_ERROR_SEVERITY);
+ 	new_csv_fields = lappend_int(new_csv_fields,CSVLOG_SQL_STATE_CODE);
+ 	new_csv_fields = lappend_int(new_csv_fields,CSVLOG_MESSAGE);
+ 	new_csv_fields = lappend_int(new_csv_fields,CSVLOG_DETAIL);
+ 	new_csv_fields = lappend_int(new_csv_fields,CSVLOG_HINT);
+ 	new_csv_fields = lappend_int(new_csv_fields,CSVLOG_INTERNAL_QUERY);
+ 	new_csv_fields = lappend_int(new_csv_fields,CSVLOG_INTERNAL_QUERY_POS);
+ 	new_csv_fields = lappend_int(new_csv_fields,CSVLOG_CONTEXT);
+ 	new_csv_fields = lappend_int(new_csv_fields,CSVLOG_QUERY);
+ 	new_csv_fields = lappend_int(new_csv_fields,CSVLOG_QUERY_POS);
+ 	new_csv_fields = lappend_int(new_csv_fields,CSVLOG_LOCATION);
+ 	new_csv_fields = lappend_int(new_csv_fields,CSVLOG_APPLICATION_NAME);
+ 
+ 	/* put new list in place */
+ 	csvlog_field_list = new_csv_fields;
+ 
+ 	MemoryContextSwitchTo(oldcontext);
+ 
+ 	return;
+ }
+ 
+ 
+ /*
+  * Process the list of fields to be sent to the CSV log file
+  */
+ const char *
+ assign_csvlog_fields(const char *newval, bool doit, GucSource source)
+ {
+ 	/* Verify the list is valid */
+ 	List		*new_csv_fields = NIL;
+ 	List		*column_list = NIL;
+ 	ListCell	*l;
+ 	char		*rawstring;
+ 	MemoryContext oldcontext;
+ 
+ 	/* Need a modifyable version to pass to SplitIdentifierString */
+ 	rawstring = pstrdup(newval);
+ 
+     /* Parse string into list of identifiers */
+     if (!SplitIdentifierString(rawstring, ',', &column_list))
+ 	{
+ 		list_free(column_list);
+ 		return NULL;
+ 	}
+ 
+ 	/*
+ 	 * We need the allocations done for the csvlog_field_list to
+ 	 * be preserved, so allocate them in TopMemoryContext.
+ 	 */
+ 	oldcontext = MemoryContextSwitchTo(TopMemoryContext);
+ 
+ 	/*
+ 	 * Loop through all of the fields provided by the user and build
+ 	 * up our new_csv_fields list which will be processed by write_csvlog
+ 	 */
+ 	foreach(l, column_list)
+ 	{
+ 		if (pg_strcasecmp(lfirst(l),"log_time") == 0)
+ 			new_csv_fields = lappend_int(new_csv_fields,CSVLOG_LOG_TIME);
+ 		else if (pg_strcasecmp(lfirst(l),"user_name") == 0)
+ 			new_csv_fields = lappend_int(new_csv_fields,CSVLOG_USER_NAME);
+ 		else if (pg_strcasecmp(lfirst(l),"role_name") == 0)
+ 			new_csv_fields = lappend_int(new_csv_fields,CSVLOG_ROLE_NAME);
+ 		else if (pg_strcasecmp(lfirst(l),"database_name") == 0)
+ 			new_csv_fields = lappend_int(new_csv_fields,CSVLOG_DATABASE_NAME);
+ 		else if (pg_strcasecmp(lfirst(l),"process_id") == 0)
+ 			new_csv_fields = lappend_int(new_csv_fields,CSVLOG_PROCESS_ID);
+ 		else if (pg_strcasecmp(lfirst(l),"connection_from") == 0)
+ 			new_csv_fields = lappend_int(new_csv_fields,CSVLOG_CONNECTION_FROM);
+ 		else if (pg_strcasecmp(lfirst(l),"session_id") == 0)
+ 			new_csv_fields = lappend_int(new_csv_fields,CSVLOG_SESSION_ID);
+ 		else if (pg_strcasecmp(lfirst(l),"session_line_num") == 0)
+ 			new_csv_fields = lappend_int(new_csv_fields,CSVLOG_SESSION_LINE_NUM);
+ 		else if (pg_strcasecmp(lfirst(l),"command_tag") == 0)
+ 			new_csv_fields = lappend_int(new_csv_fields,CSVLOG_COMMAND_TAG);
+ 		else if (pg_strcasecmp(lfirst(l),"session_start_time") == 0)
+ 			new_csv_fields = lappend_int(new_csv_fields,CSVLOG_SESSION_START_TIME);
+ 		else if (pg_strcasecmp(lfirst(l),"virtual_transaction_id") == 0)
+ 			new_csv_fields = lappend_int(new_csv_fields,CSVLOG_VIRTUAL_TRANSACTION_ID);
+ 		else if (pg_strcasecmp(lfirst(l),"transaction_id") == 0)
+ 			new_csv_fields = lappend_int(new_csv_fields,CSVLOG_TRANSACTION_ID);
+ 		else if (pg_strcasecmp(lfirst(l),"error_severity") == 0)
+ 			new_csv_fields = lappend_int(new_csv_fields,CSVLOG_ERROR_SEVERITY);
+ 		else if (pg_strcasecmp(lfirst(l),"sql_state_code") == 0)
+ 			new_csv_fields = lappend_int(new_csv_fields,CSVLOG_SQL_STATE_CODE);
+ 		else if (pg_strcasecmp(lfirst(l),"message") == 0)
+ 			new_csv_fields = lappend_int(new_csv_fields,CSVLOG_MESSAGE);
+ 		else if (pg_strcasecmp(lfirst(l),"detail") == 0)
+ 			new_csv_fields = lappend_int(new_csv_fields,CSVLOG_DETAIL);
+ 		else if (pg_strcasecmp(lfirst(l),"hint") == 0)
+ 			new_csv_fields = lappend_int(new_csv_fields,CSVLOG_HINT);
+ 		else if (pg_strcasecmp(lfirst(l),"internal_query") == 0)
+ 			new_csv_fields = lappend_int(new_csv_fields,CSVLOG_INTERNAL_QUERY);
+ 		else if (pg_strcasecmp(lfirst(l),"internal_query_pos") == 0)
+ 			new_csv_fields = lappend_int(new_csv_fields,CSVLOG_INTERNAL_QUERY_POS);
+ 		else if (pg_strcasecmp(lfirst(l),"context") == 0)
+ 			new_csv_fields = lappend_int(new_csv_fields,CSVLOG_CONTEXT);
+ 		else if (pg_strcasecmp(lfirst(l),"query") == 0)
+ 			new_csv_fields = lappend_int(new_csv_fields,CSVLOG_QUERY);
+ 		else if (pg_strcasecmp(lfirst(l),"query_pos") == 0)
+ 			new_csv_fields = lappend_int(new_csv_fields,CSVLOG_QUERY_POS);
+ 		else if (pg_strcasecmp(lfirst(l),"location") == 0)
+ 			new_csv_fields = lappend_int(new_csv_fields,CSVLOG_LOCATION);
+ 		else if (pg_strcasecmp(lfirst(l),"application_name") == 0)
+ 			new_csv_fields = lappend_int(new_csv_fields,CSVLOG_APPLICATION_NAME);
+ 		else
+ 		{
+ 			/* handle error, might need to do better than this */
+ 			return NULL;
+ 		}
+ 	}
+ 
+ 	if (doit)
+ 	{
+ 		/* put new list in place */
+ 		List *old_list = csvlog_field_list;
+ 
+ 		csvlog_field_list = new_csv_fields;
+ 
+ 		list_free(old_list);
+ 	}
+ 
+ 	/* Switch back to the calling context */
+ 	MemoryContextSwitchTo(oldcontext);
+ 
+ 	return newval;
+ }
+ 
+ /*
   * append a CSV'd version of a string to a StringInfo
   * We use the PostgreSQL defaults for CSV, i.e. quote = escape = '"'
   * If it's NULL, append nothing.
***************
*** 1946,1957 **** appendCSVLiteral(StringInfo buf, const char *data)
  }
  
  /*
!  * Constructs the error message, depending on the Errordata it gets, in a CSV
!  * format which is described in doc/src/sgml/config.sgml.
   */
  static void
  write_csvlog(ErrorData *edata)
  {
  	StringInfoData buf;
  	bool		print_stmt = false;
  
--- 2132,2145 ----
  }
  
  /*
!  * Constructs the error message, depending on the Errordata it gets, in the CSV
!  * format requested by the user, based on the csvlog_fields GUC.
   */
  static void
  write_csvlog(ErrorData *edata)
  {
+ 	int			num_fields;
+ 	bool		first_field = true;
  	StringInfoData buf;
  	bool		print_stmt = false;
  
***************
*** 1961,1966 **** write_csvlog(ErrorData *edata)
--- 2149,2158 ----
  	/* has counter been reset in current process? */
  	static int	log_my_pid = 0;
  
+ 	ListCell	*l;
+ 
+ 	const char *session_auth = show_session_authorization();
+ 
  	/*
  	 * This is one of the few places where we'd rather not inherit a static
  	 * variable's value from the postmaster.  But since we will, reset it when
***************
*** 1977,2134 **** write_csvlog(ErrorData *edata)
  	initStringInfo(&buf);
  
  	/*
! 	 * timestamp with milliseconds
! 	 *
! 	 * Check if the timestamp is already calculated for the syslog message,
! 	 * and use it if so.  Otherwise, get the current timestamp.  This is done
! 	 * to put same timestamp in both syslog and csvlog messages.
  	 */
! 	if (formatted_log_time[0] == '\0')
! 		setup_formatted_log_time();
  
! 	appendStringInfoString(&buf, formatted_log_time);
! 	appendStringInfoChar(&buf, ',');
  
! 	/* username */
! 	if (MyProcPort)
! 		appendCSVLiteral(&buf, MyProcPort->user_name);
! 	appendStringInfoChar(&buf, ',');
  
! 	/* database name */
! 	if (MyProcPort)
! 		appendCSVLiteral(&buf, MyProcPort->database_name);
! 	appendStringInfoChar(&buf, ',');
  
! 	/* Process id  */
! 	if (MyProcPid != 0)
! 		appendStringInfo(&buf, "%d", MyProcPid);
! 	appendStringInfoChar(&buf, ',');
  
! 	/* Remote host and port */
! 	if (MyProcPort && MyProcPort->remote_host)
! 	{
! 		appendStringInfoChar(&buf, '"');
! 		appendStringInfoString(&buf, MyProcPort->remote_host);
! 		if (MyProcPort->remote_port && MyProcPort->remote_port[0] != '\0')
! 		{
! 			appendStringInfoChar(&buf, ':');
! 			appendStringInfoString(&buf, MyProcPort->remote_port);
! 		}
! 		appendStringInfoChar(&buf, '"');
! 	}
! 	appendStringInfoChar(&buf, ',');
  
! 	/* session id */
! 	appendStringInfo(&buf, "%lx.%x", (long) MyStartTime, MyProcPid);
! 	appendStringInfoChar(&buf, ',');
  
! 	/* Line number */
! 	appendStringInfo(&buf, "%ld", log_line_number);
! 	appendStringInfoChar(&buf, ',');
  
! 	/* PS display */
! 	if (MyProcPort)
! 	{
! 		StringInfoData msgbuf;
! 		const char *psdisp;
! 		int			displen;
  
! 		initStringInfo(&msgbuf);
  
! 		psdisp = get_ps_display(&displen);
! 		appendBinaryStringInfo(&msgbuf, psdisp, displen);
! 		appendCSVLiteral(&buf, msgbuf.data);
  
! 		pfree(msgbuf.data);
! 	}
! 	appendStringInfoChar(&buf, ',');
  
! 	/* session start timestamp */
! 	if (formatted_start_time[0] == '\0')
! 		setup_formatted_start_time();
! 	appendStringInfoString(&buf, formatted_start_time);
! 	appendStringInfoChar(&buf, ',');
  
! 	/* Virtual transaction id */
! 	/* keep VXID format in sync with lockfuncs.c */
! 	if (MyProc != NULL && MyProc->backendId != InvalidBackendId)
! 		appendStringInfo(&buf, "%d/%u", MyProc->backendId, MyProc->lxid);
! 	appendStringInfoChar(&buf, ',');
  
! 	/* Transaction id */
! 	appendStringInfo(&buf, "%u", GetTopTransactionIdIfAny());
! 	appendStringInfoChar(&buf, ',');
  
! 	/* Error severity */
! 	appendStringInfoString(&buf, error_severity(edata->elevel));
! 	appendStringInfoChar(&buf, ',');
  
! 	/* SQL state code */
! 	appendStringInfoString(&buf, unpack_sql_state(edata->sqlerrcode));
! 	appendStringInfoChar(&buf, ',');
  
! 	/* errmessage */
! 	appendCSVLiteral(&buf, edata->message);
! 	appendStringInfoChar(&buf, ',');
  
! 	/* errdetail or errdetail_log */
! 	if (edata->detail_log)
! 		appendCSVLiteral(&buf, edata->detail_log);
! 	else
! 		appendCSVLiteral(&buf, edata->detail);
! 	appendStringInfoChar(&buf, ',');
  
! 	/* errhint */
! 	appendCSVLiteral(&buf, edata->hint);
! 	appendStringInfoChar(&buf, ',');
  
! 	/* internal query */
! 	appendCSVLiteral(&buf, edata->internalquery);
! 	appendStringInfoChar(&buf, ',');
  
! 	/* if printed internal query, print internal pos too */
! 	if (edata->internalpos > 0 && edata->internalquery != NULL)
! 		appendStringInfo(&buf, "%d", edata->internalpos);
! 	appendStringInfoChar(&buf, ',');
  
! 	/* errcontext */
! 	appendCSVLiteral(&buf, edata->context);
! 	appendStringInfoChar(&buf, ',');
  
! 	/* user query --- only reported if not disabled by the caller */
! 	if (is_log_level_output(edata->elevel, log_min_error_statement) &&
! 		debug_query_string != NULL &&
! 		!edata->hide_stmt)
! 		print_stmt = true;
! 	if (print_stmt)
! 		appendCSVLiteral(&buf, debug_query_string);
! 	appendStringInfoChar(&buf, ',');
! 	if (print_stmt && edata->cursorpos > 0)
! 		appendStringInfo(&buf, "%d", edata->cursorpos);
! 	appendStringInfoChar(&buf, ',');
! 
! 	/* file error location */
! 	if (Log_error_verbosity >= PGERROR_VERBOSE)
! 	{
! 		StringInfoData msgbuf;
! 
! 		initStringInfo(&msgbuf);
! 
! 		if (edata->funcname && edata->filename)
! 			appendStringInfo(&msgbuf, "%s, %s:%d",
! 							 edata->funcname, edata->filename,
! 							 edata->lineno);
! 		else if (edata->filename)
! 			appendStringInfo(&msgbuf, "%s:%d",
! 							 edata->filename, edata->lineno);
! 		appendCSVLiteral(&buf, msgbuf.data);
! 		pfree(msgbuf.data);
! 	}
! 	appendStringInfoChar(&buf, ',');
  
! 	/* application name */
! 	if (application_name)
! 		appendCSVLiteral(&buf, application_name);
  
  	appendStringInfoChar(&buf, '\n');
  
--- 2169,2417 ----
  	initStringInfo(&buf);
  
  	/*
! 	 * Get the number of fields, so we make sure to *not* include a comma
! 	 * after the last field.
  	 */
! 	num_fields = list_length(csvlog_field_list);
  
! 	/*
! 	 * Loop through the fields requested by the user, in the order requested, in
! 	 * the csvlog_fields GUC.
! 	 */
! 	foreach(l, csvlog_field_list)
! 	{
! 		/* If this isn't the first field, prepend a comma to seperate this
! 		 * field from the previous one */
! 		if (!first_field)
! 			appendStringInfoChar(&buf, ',');
! 		else
! 			first_field = false;
  
! 		switch (lfirst_int(l))
! 		{
! 			case CSVLOG_LOG_TIME:
! 				{
! 					/*
! 					 * timestamp with milliseconds
! 					 *
! 					 * Check if the timestamp is already calculated for the syslog message,
! 					 * and use it if so.  Otherwise, get the current timestamp.  This is done
! 					 * to put same timestamp in both syslog and csvlog messages.
! 					 */
! 					if (formatted_log_time[0] == '\0')
! 						setup_formatted_log_time();
! 
! 					appendStringInfoString(&buf, formatted_log_time);
! 				}
! 				break;
  
! 			case CSVLOG_USER_NAME:
! 				{
! 					/* session username, as done for %u */
! 					if (*session_auth != '\0')
! 						appendCSVLiteral(&buf, session_auth);
! 					else
! 						/* username */
! 						if (MyProcPort)
! 						{
! 							const char *username = MyProcPort->user_name;
! 							if (username == NULL || *username == '\0')
! 								username = _("[unknown]");
! 							appendCSVLiteral(&buf, MyProcPort->user_name);
! 						}
! 				}
! 				break;
  
! 			case CSVLOG_ROLE_NAME:
! 				/* current role, not updated if someone renames it in another
! 				 * session, of course */
! 				appendCSVLiteral(&buf, show_role());
! 				break;
  
! 			case CSVLOG_DATABASE_NAME:
! 				{
! 					/* database name */
! 					if (MyProcPort)
! 						appendCSVLiteral(&buf, MyProcPort->database_name);
! 				}
! 				break;
  
! 			case CSVLOG_PROCESS_ID:
! 				{
! 					/* Process id  */
! 					if (MyProcPid != 0)
! 						appendStringInfo(&buf, "%d", MyProcPid);
! 				}
! 				break;
  
! 			case CSVLOG_CONNECTION_FROM:
! 				{
! 					/* Remote host and port */
! 					if (MyProcPort && MyProcPort->remote_host)
! 					{
! 						appendStringInfoChar(&buf, '"');
! 						appendStringInfoString(&buf, MyProcPort->remote_host);
! 						if (MyProcPort->remote_port && MyProcPort->remote_port[0] != '\0')
! 						{
! 							appendStringInfoChar(&buf, ':');
! 							appendStringInfoString(&buf, MyProcPort->remote_port);
! 						}
! 						appendStringInfoChar(&buf, '"');
! 					}
! 				}
! 				break;
  
! 			case CSVLOG_SESSION_ID:
! 				/* session id */
! 				appendStringInfo(&buf, "%lx.%x", (long) MyStartTime, MyProcPid);
! 				break;
  
! 			case CSVLOG_SESSION_LINE_NUM:
! 				/* Line number */
! 				appendStringInfo(&buf, "%ld", log_line_number);
! 				break;
  
! 			case CSVLOG_COMMAND_TAG:
! 				{
! 					/* PS display */
! 					if (MyProcPort)
! 					{
! 						StringInfoData msgbuf;
! 						const char *psdisp;
! 						int			displen;
  
! 						initStringInfo(&msgbuf);
  
! 						psdisp = get_ps_display(&displen);
! 						appendBinaryStringInfo(&msgbuf, psdisp, displen);
! 						appendCSVLiteral(&buf, msgbuf.data);
  
! 						pfree(msgbuf.data);
! 					}
! 				}
! 				break;
  
! 			case CSVLOG_SESSION_START_TIME:
! 				{
! 					/* session start timestamp */
! 					if (formatted_start_time[0] == '\0')
! 						setup_formatted_start_time();
! 					appendStringInfoString(&buf, formatted_start_time);
! 				}
! 				break;
  
! 			case CSVLOG_VIRTUAL_TRANSACTION_ID:
! 				{
! 					/* Virtual transaction id */
! 					/* keep VXID format in sync with lockfuncs.c */
! 					if (MyProc != NULL && MyProc->backendId != InvalidBackendId)
! 						appendStringInfo(&buf, "%d/%u", MyProc->backendId, MyProc->lxid);
! 				}
! 				break;
  
! 			case CSVLOG_TRANSACTION_ID:
! 				/* Transaction id */
! 				appendStringInfo(&buf, "%u", GetTopTransactionIdIfAny());
! 				break;
  
! 			case CSVLOG_ERROR_SEVERITY:
! 				/* Error severity */
! 				appendStringInfoString(&buf, error_severity(edata->elevel));
! 				break;
  
! 			case CSVLOG_SQL_STATE_CODE:
! 				/* SQL state code */
! 				appendStringInfoString(&buf, unpack_sql_state(edata->sqlerrcode));
! 				break;
  
! 			case CSVLOG_MESSAGE:
! 				/* errmessage */
! 				appendCSVLiteral(&buf, edata->message);
! 				break;
  
! 			case CSVLOG_DETAIL:
! 				{
! 					/* errdetail or errdetail_log */
! 					if (edata->detail_log)
! 						appendCSVLiteral(&buf, edata->detail_log);
! 					else
! 						appendCSVLiteral(&buf, edata->detail);
! 				}
! 				break;
  
! 			case CSVLOG_HINT:
! 				/* errhint */
! 				appendCSVLiteral(&buf, edata->hint);
! 				break;
  
! 			case CSVLOG_INTERNAL_QUERY:
! 				/* internal query */
! 				appendCSVLiteral(&buf, edata->internalquery);
! 				break;
  
! 			case CSVLOG_INTERNAL_QUERY_POS:
! 				{
! 					/* if printed internal query, print internal pos too */
! 					if (edata->internalpos > 0 && edata->internalquery != NULL)
! 						appendStringInfo(&buf, "%d", edata->internalpos);
! 				}
! 				break;
! 
! 			case CSVLOG_CONTEXT:
! 				/* errcontext */
! 				appendCSVLiteral(&buf, edata->context);
! 				break;
! 
! 			case CSVLOG_QUERY:
! 				{
! 					/* user query --- only reported if not disabled by the caller */
! 					if (is_log_level_output(edata->elevel, log_min_error_statement) &&
! 						debug_query_string != NULL &&
! 						!edata->hide_stmt)
! 						print_stmt = true;
! 					if (print_stmt)
! 						appendCSVLiteral(&buf, debug_query_string);
! 				}
! 				break;
! 
! 			case CSVLOG_QUERY_POS:
! 				{
! 					if (print_stmt && edata->cursorpos > 0)
! 						appendStringInfo(&buf, "%d", edata->cursorpos);
! 				}
! 				break;
! 
! 			case CSVLOG_LOCATION:
! 				{
! 					/* file error location */
! 					if (Log_error_verbosity >= PGERROR_VERBOSE)
! 					{
! 						StringInfoData msgbuf;
! 
! 						initStringInfo(&msgbuf);
! 
! 						if (edata->funcname && edata->filename)
! 							appendStringInfo(&msgbuf, "%s, %s:%d",
! 											 edata->funcname, edata->filename,
! 											 edata->lineno);
! 						else if (edata->filename)
! 							appendStringInfo(&msgbuf, "%s:%d",
! 											 edata->filename, edata->lineno);
! 						appendCSVLiteral(&buf, msgbuf.data);
! 						pfree(msgbuf.data);
! 					}
! 				}
! 				break;
  
! 			case CSVLOG_APPLICATION_NAME:
! 				{
! 					/* application name */
! 					if (application_name)
! 						appendCSVLiteral(&buf, application_name);
! 				}
! 				break;
! 		}
! 	}
  
  	appendStringInfoChar(&buf, '\n');
  
***************
*** 2139,2144 **** write_csvlog(ErrorData *edata)
--- 2422,2429 ----
  		write_pipe_chunks(buf.data, buf.len, LOG_DESTINATION_CSVLOG);
  
  	pfree(buf.data);
+ 
+ 	return;
  }
  
  /*
*** a/src/backend/utils/misc/guc.c
--- b/src/backend/utils/misc/guc.c
***************
*** 64,69 ****
--- 64,70 ----
  #include "tsearch/ts_cache.h"
  #include "utils/builtins.h"
  #include "utils/bytea.h"
+ #include "utils/elog.h"
  #include "utils/guc_tables.h"
  #include "utils/memutils.h"
  #include "utils/pg_locale.h"
***************
*** 190,195 **** static char *config_enum_get_options(struct config_enum * record,
--- 191,199 ----
  						const char *prefix, const char *suffix,
  						const char *separator);
  
+ /* Needs to be defined here because elog.h can't #include guc.h */
+ extern const char *assign_csvlog_fields(const char *newval,
+                 bool doit, GucSource source);
  
  /*
   * Options for enum values defined in this module.
***************
*** 2315,2320 **** static struct config_string ConfigureNamesString[] =
--- 2319,2335 ----
  	},
  
  	{
+ 		{"csvlog_fields", PGC_POSTMASTER, LOGGING_WHAT,
+ 			gettext_noop("Controls fields logged to CSV logfiles."),
+ 			gettext_noop("If blank, the default set of fields is used."),
+ 			GUC_LIST_INPUT
+ 		},
+ 		&csvlog_fields,
+ 		"log_time, user_name, database_name, process_id, connection_from, session_id, session_line_num, command_tag, session_start_time, virtual_transaction_id, transaction_id, error_severity, sql_state_code, message, detail, hint, internal_query, internal_query_pos, context, query, query_pos, location, application_name",
+ 		assign_csvlog_fields, NULL
+ 	},
+ 
+ 	{
  		{"log_timezone", PGC_SIGHUP, LOGGING_WHAT,
  			gettext_noop("Sets the time zone to use in log messages."),
  			NULL
***************
*** 3464,3469 **** InitializeGUCOptions(void)
--- 3479,3490 ----
  	pg_timezone_pre_initialize();
  
  	/*
+ 	 * Ditto for csvlog_fields, have to set it to something before we get
+ 	 * too far along.
+ 	 */
+ 	build_default_csvlog_list();
+ 
+ 	/*
  	 * Build sorted array of all GUC variables.
  	 */
  	build_guc_variables();
*** a/src/backend/utils/misc/postgresql.conf.sample
--- b/src/backend/utils/misc/postgresql.conf.sample
***************
*** 377,382 ****
--- 377,386 ----
  					#        processes
  					#   %% = '%'
  					# e.g. '<%u%%%d> '
+ 
+ # fields to include in the CSV log output
+ #csvlog_fields = 'log_time, user_name, database_name, process_id, connection_from, session_id, session_line_num, command_tag, session_start_time, virtual_transaction_id, transaction_id, error_severity, sql_state_code, message, detail, hint, internal_query, internal_query_pos, context, query, query_pos, location, application_name'
+ 
  #log_lock_waits = off			# log lock waits >= deadlock_timeout
  #log_statement = 'none'			# none, ddl, mod, all
  #log_temp_files = -1			# log temporary files equal or larger
*** a/src/include/utils/elog.h
--- b/src/include/utils/elog.h
***************
*** 330,337 **** typedef enum
--- 330,366 ----
  
  extern int	Log_error_verbosity;
  extern char *Log_line_prefix;
+ extern char *csvlog_fields;
  extern int	Log_destination;
  
+ typedef enum LogCSVFields
+ {
+ 	CSVLOG_LOG_TIME,
+ 	CSVLOG_USER_NAME,
+ 	CSVLOG_ROLE_NAME,
+ 	CSVLOG_DATABASE_NAME,
+ 	CSVLOG_PROCESS_ID,
+ 	CSVLOG_CONNECTION_FROM,
+ 	CSVLOG_SESSION_ID,
+ 	CSVLOG_SESSION_LINE_NUM,
+ 	CSVLOG_COMMAND_TAG,
+ 	CSVLOG_SESSION_START_TIME,
+ 	CSVLOG_VIRTUAL_TRANSACTION_ID,
+ 	CSVLOG_TRANSACTION_ID,
+ 	CSVLOG_ERROR_SEVERITY,
+ 	CSVLOG_SQL_STATE_CODE,
+ 	CSVLOG_MESSAGE,
+ 	CSVLOG_DETAIL,
+ 	CSVLOG_HINT,
+ 	CSVLOG_INTERNAL_QUERY,
+ 	CSVLOG_INTERNAL_QUERY_POS,
+ 	CSVLOG_CONTEXT,
+ 	CSVLOG_QUERY,
+ 	CSVLOG_QUERY_POS,
+ 	CSVLOG_LOCATION,
+ 	CSVLOG_APPLICATION_NAME
+ } LogCSVFields;
+ 
  /* Log destination bitmap */
  #define LOG_DESTINATION_STDERR	 1
  #define LOG_DESTINATION_SYSLOG	 2
***************
*** 343,348 **** extern void DebugFileOpen(void);
--- 372,382 ----
  extern char *unpack_sql_state(int sql_state);
  extern bool in_error_recursion_trouble(void);
  
+ /* Used by guc.c to set up the default set of
+  * csv fields to log
+  */
+ extern void build_default_csvlog_list(void);
+ 
  #ifdef HAVE_SYSLOG
  extern void set_syslog_parameters(const char *ident, int facility);
  #endif
*** a/src/tools/pgindent/typedefs.list
--- b/src/tools/pgindent/typedefs.list
***************
*** 855,860 **** LockTagType
--- 855,861 ----
  LockTupleMode
  LockingClause
  LogStmtLevel
+ LogCSVFields
  LogicalTape
  LogicalTapeSet
  MAGIC

*** a/doc/src/sgml/config.sgml
--- b/doc/src/sgml/config.sgml
***************
*** 5188,5202 **** dynamic_library_path = 'C:\tools\postgresql;H:\my_project\lib;$libdir'
        </listitem>
       </varlistentry>
  
!      <varlistentry id="guc-max-predicate-locks-per-transaction" xreflabel="max_predicate_locks_per_transaction">
!       <term><varname>max_predicate_locks_per_transaction</varname> (<type>integer</type>)</term>
        <indexterm>
!        <primary><varname>max_predicate_locks_per_transaction</> configuration parameter</primary>
        </indexterm>
        <listitem>
         <para>
          The shared predicate lock table tracks locks on
!         <varname>max_predicate_locks_per_transaction</varname> * (<xref
          linkend="guc-max-connections"> + <xref
          linkend="guc-max-prepared-transactions">) objects (e.g., tables);
          hence, no more than this many distinct objects can be locked at
--- 5188,5202 ----
        </listitem>
       </varlistentry>
  
!      <varlistentry id="guc-max-pred-locks-per-transaction" xreflabel="max_pred_locks_per_transaction">
!       <term><varname>max_pred_locks_per_transaction</varname> (<type>integer</type>)</term>
        <indexterm>
!        <primary><varname>max_pred_locks_per_transaction</> configuration parameter</primary>
        </indexterm>
        <listitem>
         <para>
          The shared predicate lock table tracks locks on
!         <varname>max_pred_locks_per_transaction</varname> * (<xref
          linkend="guc-max-connections"> + <xref
          linkend="guc-max-prepared-transactions">) objects (e.g., tables);
          hence, no more than this many distinct objects can be locked at
*** a/src/backend/storage/lmgr/predicate.c
--- b/src/backend/storage/lmgr/predicate.c
***************
*** 1874,1880 **** DeleteChildTargetLocks(const PREDICATELOCKTARGETTAG *newtargettag)
   * thresholds are, either making it proportional to the number of
   * tuples in a page & pages in a relation, or at least making it a
   * GUC. Currently the threshold is 3 for a page lock, and
!  * max_predicate_locks_per_transaction/2 for a relation lock, chosen
   * entirely arbitrarily (and without benchmarking).
   */
  static int
--- 1874,1880 ----
   * thresholds are, either making it proportional to the number of
   * tuples in a page & pages in a relation, or at least making it a
   * GUC. Currently the threshold is 3 for a page lock, and
!  * max_pred_locks_per_transaction/2 for a relation lock, chosen
   * entirely arbitrarily (and without benchmarking).
   */
  static int
***************
*** 2063,2069 **** CreatePredicateLock(const PREDICATELOCKTARGETTAG *targettag,
  		ereport(ERROR,
  				(errcode(ERRCODE_OUT_OF_MEMORY),
  				 errmsg("out of shared memory"),
! 				 errhint("You might need to increase max_predicate_locks_per_transaction.")));
  	if (!found)
  	{
  		SHMQueueInit(&(target->predicateLocks));
--- 2063,2069 ----
  		ereport(ERROR,
  				(errcode(ERRCODE_OUT_OF_MEMORY),
  				 errmsg("out of shared memory"),
! 				 errhint("You might need to increase max_pred_locks_per_transaction.")));
  	if (!found)
  	{
  		SHMQueueInit(&(target->predicateLocks));
***************
*** 2082,2088 **** CreatePredicateLock(const PREDICATELOCKTARGETTAG *targettag,
  		ereport(ERROR,
  				(errcode(ERRCODE_OUT_OF_MEMORY),
  				 errmsg("out of shared memory"),
! 				 errhint("You might need to increase max_predicate_locks_per_transaction.")));
  
  	if (!found)
  	{
--- 2082,2088 ----
  		ereport(ERROR,
  				(errcode(ERRCODE_OUT_OF_MEMORY),
  				 errmsg("out of shared memory"),
! 				 errhint("You might need to increase max_pred_locks_per_transaction.")));
  
  	if (!found)
  	{
***************
*** 2341,2347 **** PredicateLockTupleRowVersionLink(const Relation relation,
  			ereport(ERROR,
  					(errcode(ERRCODE_OUT_OF_MEMORY),
  					 errmsg("out of shared memory"),
! 					 errhint("You might need to increase max_predicate_locks_per_transaction.")));
  		if (!found)
  		{
  			SHMQueueInit(&(newtarget->predicateLocks));
--- 2341,2347 ----
  			ereport(ERROR,
  					(errcode(ERRCODE_OUT_OF_MEMORY),
  					 errmsg("out of shared memory"),
! 					 errhint("You might need to increase max_pred_locks_per_transaction.")));
  		if (!found)
  		{
  			SHMQueueInit(&(newtarget->predicateLocks));
***************
*** 3337,3343 **** ReleaseOneSerializableXact(SERIALIZABLEXACT *sxact, bool partial,
  				ereport(ERROR,
  						(errcode(ERRCODE_OUT_OF_MEMORY),
  						 errmsg("out of shared memory"),
! 						 errhint("You might need to increase max_predicate_locks_per_transaction.")));
  			if (found)
  			{
  				if (predlock->commitSeqNo < sxact->commitSeqNo)
--- 3337,3343 ----
  				ereport(ERROR,
  						(errcode(ERRCODE_OUT_OF_MEMORY),
  						 errmsg("out of shared memory"),
! 						 errhint("You might need to increase max_pred_locks_per_transaction.")));
  			if (found)
  			{
  				if (predlock->commitSeqNo < sxact->commitSeqNo)
*** a/src/backend/utils/misc/guc.c
--- b/src/backend/utils/misc/guc.c
***************
*** 1725,1734 **** static struct config_int ConfigureNamesInt[] =
  	},
  
  	{
! 		{"max_predicate_locks_per_transaction", PGC_POSTMASTER, LOCK_MANAGEMENT,
  			gettext_noop("Sets the maximum number of predicate locks per transaction."),
  			gettext_noop("The shared predicate lock table is sized on the assumption that "
! 			  "at most max_predicate_locks_per_transaction * max_connections distinct "
  						 "objects will need to be locked at any one time.")
  		},
  		&max_predicate_locks_per_xact,
--- 1725,1734 ----
  	},
  
  	{
! 		{"max_pred_locks_per_transaction", PGC_POSTMASTER, LOCK_MANAGEMENT,
  			gettext_noop("Sets the maximum number of predicate locks per transaction."),
  			gettext_noop("The shared predicate lock table is sized on the assumption that "
! 			  "at most max_pred_locks_per_transaction * max_connections distinct "
  						 "objects will need to be locked at any one time.")
  		},
  		&max_predicate_locks_per_xact,

*** a/doc/src/sgml/config.sgml
--- b/doc/src/sgml/config.sgml
***************
*** 5188,5202 **** dynamic_library_path = 'C:\tools\postgresql;H:\my_project\lib;$libdir'
        </listitem>
       </varlistentry>
  
!      <varlistentry id="guc-max-predicate-locks-per-transaction" xreflabel="max_predicate_locks_per_transaction">
!       <term><varname>max_predicate_locks_per_transaction</varname> (<type>integer</type>)</term>
        <indexterm>
!        <primary><varname>max_predicate_locks_per_transaction</> configuration parameter</primary>
        </indexterm>
        <listitem>
         <para>
          The shared predicate lock table tracks locks on
!         <varname>max_predicate_locks_per_transaction</varname> * (<xref
          linkend="guc-max-connections"> + <xref
          linkend="guc-max-prepared-transactions">) objects (e.g., tables);
          hence, no more than this many distinct objects can be locked at
--- 5188,5202 ----
        </listitem>
       </varlistentry>
  
!      <varlistentry id="guc-max-pred-locks-per-transaction" xreflabel="max_pred_locks_per_transaction">
!       <term><varname>max_pred_locks_per_transaction</varname> (<type>integer</type>)</term>
        <indexterm>
!        <primary><varname>max_pred_locks_per_transaction</> configuration parameter</primary>
        </indexterm>
        <listitem>
         <para>
          The shared predicate lock table tracks locks on
!         <varname>max_pred_locks_per_transaction</varname> * (<xref
          linkend="guc-max-connections"> + <xref
          linkend="guc-max-prepared-transactions">) objects (e.g., tables);
          hence, no more than this many distinct objects can be locked at
*** a/src/backend/storage/lmgr/predicate.c
--- b/src/backend/storage/lmgr/predicate.c
***************
*** 1874,1880 **** DeleteChildTargetLocks(const PREDICATELOCKTARGETTAG *newtargettag)
   * thresholds are, either making it proportional to the number of
   * tuples in a page & pages in a relation, or at least making it a
   * GUC. Currently the threshold is 3 for a page lock, and
!  * max_predicate_locks_per_transaction/2 for a relation lock, chosen
   * entirely arbitrarily (and without benchmarking).
   */
  static int
--- 1874,1880 ----
   * thresholds are, either making it proportional to the number of
   * tuples in a page & pages in a relation, or at least making it a
   * GUC. Currently the threshold is 3 for a page lock, and
!  * max_pred_locks_per_transaction/2 for a relation lock, chosen
   * entirely arbitrarily (and without benchmarking).
   */
  static int
***************
*** 2063,2069 **** CreatePredicateLock(const PREDICATELOCKTARGETTAG *targettag,
  		ereport(ERROR,
  				(errcode(ERRCODE_OUT_OF_MEMORY),
  				 errmsg("out of shared memory"),
! 				 errhint("You might need to increase max_predicate_locks_per_transaction.")));
  	if (!found)
  	{
  		SHMQueueInit(&(target->predicateLocks));
--- 2063,2069 ----
  		ereport(ERROR,
  				(errcode(ERRCODE_OUT_OF_MEMORY),
  				 errmsg("out of shared memory"),
! 				 errhint("You might need to increase max_pred_locks_per_transaction.")));
  	if (!found)
  	{
  		SHMQueueInit(&(target->predicateLocks));
***************
*** 2082,2088 **** CreatePredicateLock(const PREDICATELOCKTARGETTAG *targettag,
  		ereport(ERROR,
  				(errcode(ERRCODE_OUT_OF_MEMORY),
  				 errmsg("out of shared memory"),
! 				 errhint("You might need to increase max_predicate_locks_per_transaction.")));
  
  	if (!found)
  	{
--- 2082,2088 ----
  		ereport(ERROR,
  				(errcode(ERRCODE_OUT_OF_MEMORY),
  				 errmsg("out of shared memory"),
! 				 errhint("You might need to increase max_pred_locks_per_transaction.")));
  
  	if (!found)
  	{
***************
*** 2341,2347 **** PredicateLockTupleRowVersionLink(const Relation relation,
  			ereport(ERROR,
  					(errcode(ERRCODE_OUT_OF_MEMORY),
  					 errmsg("out of shared memory"),
! 					 errhint("You might need to increase max_predicate_locks_per_transaction.")));
  		if (!found)
  		{
  			SHMQueueInit(&(newtarget->predicateLocks));
--- 2341,2347 ----
  			ereport(ERROR,
  					(errcode(ERRCODE_OUT_OF_MEMORY),
  					 errmsg("out of shared memory"),
! 					 errhint("You might need to increase max_pred_locks_per_transaction.")));
  		if (!found)
  		{
  			SHMQueueInit(&(newtarget->predicateLocks));
***************
*** 3337,3343 **** ReleaseOneSerializableXact(SERIALIZABLEXACT *sxact, bool partial,
  				ereport(ERROR,
  						(errcode(ERRCODE_OUT_OF_MEMORY),
  						 errmsg("out of shared memory"),
! 						 errhint("You might need to increase max_predicate_locks_per_transaction.")));
  			if (found)
  			{
  				if (predlock->commitSeqNo < sxact->commitSeqNo)
--- 3337,3343 ----
  				ereport(ERROR,
  						(errcode(ERRCODE_OUT_OF_MEMORY),
  						 errmsg("out of shared memory"),
! 						 errhint("You might need to increase max_pred_locks_per_transaction.")));
  			if (found)
  			{
  				if (predlock->commitSeqNo < sxact->commitSeqNo)
*** a/src/backend/utils/misc/guc.c
--- b/src/backend/utils/misc/guc.c
***************
*** 1725,1734 **** static struct config_int ConfigureNamesInt[] =
  	},
  
  	{
! 		{"max_predicate_locks_per_transaction", PGC_POSTMASTER, LOCK_MANAGEMENT,
  			gettext_noop("Sets the maximum number of predicate locks per transaction."),
  			gettext_noop("The shared predicate lock table is sized on the assumption that "
! 			  "at most max_predicate_locks_per_transaction * max_connections distinct "
  						 "objects will need to be locked at any one time.")
  		},
  		&max_predicate_locks_per_xact,
--- 1725,1734 ----
  	},
  
  	{
! 		{"max_pred_locks_per_transaction", PGC_POSTMASTER, LOCK_MANAGEMENT,
  			gettext_noop("Sets the maximum number of predicate locks per transaction."),
  			gettext_noop("The shared predicate lock table is sized on the assumption that "
! 			  "at most max_pred_locks_per_transaction * max_connections distinct "
  						 "objects will need to be locked at any one time.")
  		},
  		&max_predicate_locks_per_xact,
*** a/src/backend/utils/misc/postgresql.conf.sample
--- b/src/backend/utils/misc/postgresql.conf.sample
***************
*** 503,509 ****
  # Note:  Each lock table slot uses ~270 bytes of shared memory, and there are
  # max_locks_per_transaction * (max_connections + max_prepared_transactions)
  # lock table slots.
! #max_predicate_locks_per_transaction = 64	# min 10
  					# (change requires restart)
  
  #------------------------------------------------------------------------------
--- 503,509 ----
  # Note:  Each lock table slot uses ~270 bytes of shared memory, and there are
  # max_locks_per_transaction * (max_connections + max_prepared_transactions)
  # lock table slots.
! #max_pred_locks_per_transaction = 64	# min 10
  					# (change requires restart)
  
  #------------------------------------------------------------------------------

*** a/doc/src/sgml/config.sgml
--- b/doc/src/sgml/config.sgml
***************
*** 3542,3548 **** local0.*    /var/log/postgresql
              </row>
              <row>
               <entry><literal>%u</literal></entry>
!              <entry>User name</entry>
               <entry>yes</entry>
              </row>
              <row>
--- 3542,3561 ----
              </row>
              <row>
               <entry><literal>%u</literal></entry>
!              <entry>Session user name, typically the user name which was used
!              to authenticate to <productname>PostgreSQL</productname> with,
!              but can be changed by a superuser, see <command>SET SESSION
!              AUTHORIZATION</></entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>%U</literal></entry>
!              <entry>Current role name, when set with <command>SET ROLE</>;
!              the current role identifier is relevant for permission checking;
!              Returns 'none' if the current role matches the session user.
!              Note: Log messages from inside <literal>SECURITY DEFINER</>
!              functions will show the calling role, not the effective role
!              inside the <literal>SECURITY DEFINER</> function</entry>
               <entry>yes</entry>
              </row>
              <row>
***************
*** 3659,3664 **** FROM pg_stat_activity;
--- 3672,3717 ----
        </listitem>
       </varlistentry>
  
+      <varlistentry id="guc-csvlog-fields" xreflabel="csvlog_fields">
+       <term><varname>csvlog_fields</varname> (<type>string</type>)</term>
+       <indexterm>
+        <primary><varname>csvlog_fields</> configuration parameter</primary>
+       </indexterm>
+       <listitem>
+        <para>
+         Controls the set and order of the fields which are written out in
+         the CSV-format log file.
+ 
+         The default is:
+         <literal>log_time, user_name, database_name, process_id,
+         connection_from, session_id, session_line_num, command_tag,
+         session_start_time, virtual_transaction_id, transaction_id,
+         error_severity, sql_state_code, message, detail, hint,
+         internal_query, internal_query_pos, context, query, query_pos,
+         location, application_name</literal>
+ 
+         For details on what these fields are, refer to the
+         <varname>log_line_prefix</varname> and
+         <xref linkend="runtime-config-logging-csvlog"> documentation.
+        </para>
+       </listitem>
+      </varlistentry>
+ 
+      <varlistentry id="guc-csvlog-header" xreflabel="csvlog_header">
+       <term><varname>csvlog_header</varname> (<type>boolean</type>)</term>
+       <indexterm>
+        <primary><varname>csvlog_header</> configuration parameter</primary>
+       </indexterm>
+       <listitem>
+        <para>
+         Controls if a header should be output for each file logged through
+         the CSV-format logging.
+ 
+         The default is: <literal>false</literal>, for backwards compatibility.
+        </para>
+       </listitem>
+      </varlistentry>
+ 
       <varlistentry id="guc-log-lock-waits" xreflabel="log_lock_waits">
        <term><varname>log_lock_waits</varname> (<type>boolean</type>)</term>
        <indexterm>
***************
*** 3766,3799 **** FROM pg_stat_activity;
          Including <literal>csvlog</> in the <varname>log_destination</> list
          provides a convenient way to import log files into a database table.
          This option emits log lines in comma-separated-values
!         (<acronym>CSV</>) format,
!         with these columns:
!         timestamp with milliseconds,
!         user name,
!         database name,
!         process ID,
!         client host:port number,
!         session ID,
!         per-session line number,
!         command tag,
!         session start time,
!         virtual transaction ID,
!         regular transaction ID,
!         error severity,
!         SQLSTATE code,
!         error message,
!         error message detail,
!         hint,
!         internal query that led to the error (if any),
!         character count of the error position therein,
!         error context,
!         user query that led to the error (if any and enabled by
!         <varname>log_min_error_statement</>),
!         character count of the error position therein,
!         location of the error in the PostgreSQL source code
!         (if <varname>log_error_verbosity</> is set to <literal>verbose</>),
!         and application name.
!         Here is a sample table definition for storing CSV-format log output:
  
  <programlisting>
  CREATE TABLE postgres_log
--- 3819,3971 ----
          Including <literal>csvlog</> in the <varname>log_destination</> list
          provides a convenient way to import log files into a database table.
          This option emits log lines in comma-separated-values
!         (<acronym>CSV</>) format.  The following table defines the fields
!         which can be included in the CSV output, their meanings, and if they
!         are included in the default CSV layout (the default ordering matches
!         the order of this table).
! 
!          <informaltable>
!           <tgroup cols="3">
!            <thead>
!             <row>
!              <entry>CSV Field Name</entry>
!              <entry>Definition</entry>
!              <entry>Included by Default</entry>
!              </row>
!             </thead>
!            <tbody>
!             <row>
!              <entry><literal>log_time</literal></entry>
!              <entry>timestamp with milliseconds</entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>user_name</literal></entry>
!              <entry>session user name</entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>role_name</literal></entry>
!              <entry>current role name</entry>
!              <entry>no</entry>
!             </row>
!             <row>
!              <entry><literal>database_name</literal></entry>
!              <entry>name of database connected to</entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>process_id</literal></entry>
!              <entry>process ID of the backend PG process</entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>connection_from</literal></entry>
!              <entry>client host/IP and port number</entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>session_id</literal></entry>
!              <entry>ID of the session</entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>session_line_number</literal></entry>
!              <entry>per-session line number</entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>command_tag</literal></entry>
!              <entry>Command tag of the logged command</entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>session_start_time</literal></entry>
!              <entry>Start time of the current session</entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>virtual_transaction_id</literal></entry>
!              <entry>Virtual Transaction ID</entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>transaction_id</literal></entry>
!              <entry>Regular Transaction ID</entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>error_severity</literal></entry>
!              <entry>Error severity code of the log message</entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>sql_state_code</literal></entry>
!              <entry>SQLSTATE code of the command being logged</entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>message</literal></entry>
!              <entry>Error message</entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>detail</literal></entry>
!              <entry>Error message detail</entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>hint</literal></entry>
!              <entry>Error message hint</entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>internal_query</literal></entry>
!              <entry>internal query that led to the error (if any)</entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>internal_query_pos</literal></entry>
!              <entry>character count of the error position of the internal query</entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>context</literal></entry>
!              <entry>error context</entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>query</literal></entry>
!              <entry>user query that led to the error (if any and enabled by <varname>log_min_error_statement</varname>)</entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>query_pos</literal></entry>
!              <entry>character count of the error position of the user query</entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>location</literal></entry>
!              <entry>location of the error in the PostgreSQL source code (if <varname>log_error_verbosity</varname> is set to <literal>verbose</literal>)</entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>application_name</literal></entry>
!              <entry>Name of the connecting application, if provided by the application</entry>
!              <entry>yes</entry>
!             </row>
!            </tbody>
!           </tgroup>
!          </informaltable>
! 
!         The set of columns to be included, and their order, in the CSV
!         output can be controlled using the <varname>csvlog_fields</varname> option.
! 
!         For additional details on the definition of the above columns, refer
!         to the documentation for <varname>log_line_prefix</varname>.
! 
!         Here is a sample table definition for storing the default CSV-format
!         log output:
  
  <programlisting>
  CREATE TABLE postgres_log
*** a/src/backend/commands/variable.c
--- b/src/backend/commands/variable.c
***************
*** 847,852 **** assign_session_authorization(const char *value, bool doit, GucSource source)
--- 847,857 ----
  	return result;
  }
  
+ /*
+  * function to return the stored session username, needed because we
+  * can't do catalog lookups when possibly being called after an error,
+  * eg: from elog.c or part of GUC handling.
+  */
  const char *
  show_session_authorization(void)
  {
***************
*** 972,977 **** assign_role(const char *value, bool doit, GucSource source)
--- 977,987 ----
  	return result;
  }
  
+ /*
+  * function to return the stored role username, needed because we
+  * can't do catalog lookups when possibly being called after an error,
+  * eg: from elog.c or part of GUC handling.
+  */
  const char *
  show_role(void)
  {
*** a/src/backend/postmaster/syslogger.c
--- b/src/backend/postmaster/syslogger.c
***************
*** 147,152 **** static char *logfile_getname(pg_time_t timestamp, const char *suffix);
--- 147,153 ----
  static void set_next_rotation_time(void);
  static void sigHupHandler(SIGNAL_ARGS);
  static void sigUsr1Handler(SIGNAL_ARGS);
+ static void write_csvlog_header(FILE *out_fh);
  
  
  /*
***************
*** 988,993 **** pipeThread(void *arg)
--- 989,1019 ----
  #endif   /* WIN32 */
  
  /*
+  * Internal function for writing out the header of a CSV-style log file
+  * to the passed-in file handle.
+  */
+ static void
+ write_csvlog_header(FILE *out_fh)
+ {
+ 	int				rc;
+ 	int				header_length = strlen(csvlog_fields);
+ 
+ 	/* Write out the csvlog_fields GUC, which matches the CSV log format
+ 	 * header, at least, if we did everything right. */
+ 	rc = fwrite(csvlog_fields, 1, header_length, out_fh);
+ 
+ 	/* can't use ereport here because of possible recursion */
+ 	if (rc != header_length)
+ 		write_stderr("could not write to new log file: %s\n", strerror(errno));
+ 
+ 	rc = fputc('\n', out_fh);
+ 	if (rc != '\n')
+ 		write_stderr("could not write to new log file: %s\n", strerror(errno));
+ 
+ 	return;
+ }
+ 
+ /*
   * open the csv log file - we do this opportunistically, because
   * we don't know if CSV logging will be wanted.
   */
***************
*** 995,1004 **** static void
  open_csvlogfile(void)
  {
  	char	   *filename;
  
  	filename = logfile_getname(time(NULL), ".csv");
  
! 	csvlogFile = logfile_open(filename, "a", false);
  
  	pfree(filename);
  }
--- 1021,1037 ----
  open_csvlogfile(void)
  {
  	char	   *filename;
+ 	FILE	   *fh;
  
  	filename = logfile_getname(time(NULL), ".csv");
  
! 	fh = logfile_open(filename, "a", false);
! 
! 	/* Check if we are asked to write out a header for the CSV file. */
! 	if (csvlog_header)
! 		write_csvlog_header(fh);
! 
! 	csvlogFile = fh;
  
  	pfree(filename);
  }
***************
*** 1165,1170 **** logfile_rotate(bool time_based_rotation, int size_rotation_for)
--- 1198,1207 ----
  			return;
  		}
  
+ 		/* Check if we are asked to write out a header for the CSV file. */
+ 		if (csvlog_header)
+ 			write_csvlog_header(fh);
+ 
  		fclose(csvlogFile);
  		csvlogFile = fh;
  
*** a/src/backend/utils/error/elog.c
--- b/src/backend/utils/error/elog.c
***************
*** 3,8 ****
--- 3,17 ----
   * elog.c
   *	  error logging and reporting
   *
+  * A few comments about situations where error processing is called:
+  *
+  * We need to be cautious of both a performance hit when logging, since
+  * log messages can be generated at a huge rate if every command is being
+  * logged and we also need to watch out for what can happen when we are
+  * trying to log from an aborted transaction.  Specifically, attempting to
+  * do SysCache lookups and possibly use other usually available backend
+  * systems will fail badly when logging from an aborted transaction.
+  *
   * Some notes about recursion and errors during error processing:
   *
   * We need to be robust about recursive-error scenarios --- for example,
***************
*** 59,73 ****
--- 68,85 ----
  
  #include "access/transam.h"
  #include "access/xact.h"
+ #include "commands/variable.h"
  #include "libpq/libpq.h"
  #include "libpq/pqformat.h"
  #include "mb/pg_wchar.h"
  #include "miscadmin.h"
+ #include "nodes/pg_list.h"
  #include "postmaster/postmaster.h"
  #include "postmaster/syslogger.h"
  #include "storage/ipc.h"
  #include "storage/proc.h"
  #include "tcop/tcopprot.h"
+ #include "utils/builtins.h"
  #include "utils/guc.h"
  #include "utils/memutils.h"
  #include "utils/ps_status.h"
***************
*** 93,98 **** extern bool redirection_done;
--- 105,144 ----
  int			Log_error_verbosity = PGERROR_VERBOSE;
  char	   *Log_line_prefix = NULL;		/* format for extra log line info */
  int			Log_destination = LOG_DESTINATION_STDERR;
+ char	   *csvlog_fields = NULL;
+ bool		csvlog_header = false;
+ 
+ static List *csvlog_field_list = NIL;
+ 
+ /* To add a CSV field option, you need to update the enum in elog.h, check
+  * if the last value in the enum changed and if so update MAX_CSVLOG_OPTS,
+  * add code to handle the option in write_csv(), and add it here. */
+ const char *CSVFieldNames[] = {
+ 	"log_time",					/* CSVLOG_LOG_TIME */
+ 	"user_name",				/* CSVLOG_USER_NAME */
+ 	"role_name",				/* CSVLOG_ROLE_NAME */
+ 	"database_name",			/* CSVLOG_DATABASE_NAME */
+ 	"process_id",				/* CSVLOG_PROCESS_ID */
+ 	"connection_from",			/* CSVLOG_CONNECTION_FROM */
+ 	"session_id",				/* CSVLOG_SESSION_ID */
+ 	"session_line_num",			/* CSVLOG_SESSION_LINE_NUM */
+ 	"command_tag",				/* CSVLOG_COMMAND_TAG */
+ 	"session_start_time",		/* CSVLOG_SESSION_START_TIME */
+ 	"virtual_transaction_id",	/* CSVLOG_VIRTUAL_TRANSACTION_ID */
+ 	"transaction_id",			/* CSVLOG_TRANSACTION_ID */
+ 	"error_severity",			/* CSVLOG_ERROR_SEVERITY */
+ 	"sql_state_code",			/* CSVLOG_SQL_STATE_CODE */
+ 	"message",					/* CSVLOG_MESSAGE */
+ 	"detail",					/* CSVLOG_DETAIL */
+ 	"hint",						/* CSVLOG_HINT */
+ 	"internal_query",			/* CSVLOG_INTERNAL_QUERY */
+ 	"internal_query_pos",		/* CSVLOG_INTERNAL_QUERY_POS */
+ 	"context",					/* CSVLOG_CONTEXT */
+ 	"query",					/* CSVLOG_QUERY */
+ 	"query_pos",				/* CSVLOG_QUERY_POS */
+ 	"location",					/* CSVLOG_LOCATION */
+ 	"application_name"			/* CSVLOG_APPLICATION_NAME */
+ };
  
  #ifdef HAVE_SYSLOG
  
***************
*** 161,166 **** static void write_csvlog(ErrorData *edata);
--- 207,217 ----
  static void setup_formatted_log_time(void);
  static void setup_formatted_start_time(void);
  
+ /* extern'd and used from guc.c... */
+ const char *assign_csvlog_fields(const char *newval, bool doit,
+ 								 GucSource source);
+ 
+ 
  
  /*
   * in_error_recursion_trouble --- are we at risk of infinite error recursion?
***************
*** 1817,1831 **** log_line_prefix(StringInfo buf, ErrorData *edata)
  				}
  				break;
  			case 'u':
- 				if (MyProcPort)
  				{
! 					const char *username = MyProcPort->user_name;
! 
! 					if (username == NULL || *username == '\0')
! 						username = _("[unknown]");
! 					appendStringInfoString(buf, username);
  				}
  				break;
  			case 'd':
  				if (MyProcPort)
  				{
--- 1868,1891 ----
  				}
  				break;
  			case 'u':
  				{
! 					const char *session_auth = show_session_authorization();
! 
! 					if (*session_auth != '\0')
! 						appendStringInfoString(buf, session_auth);
! 					else if (MyProcPort)
! 					{
! 						const char *username = MyProcPort->user_name;
! 
! 						if (username == NULL || *username == '\0')
! 							username = _("[unknown]");
! 						appendStringInfoString(buf, username);
! 					}
  				}
  				break;
+ 			case 'U':
+ 				appendStringInfoString(buf, show_role());
+ 				break;
  			case 'd':
  				if (MyProcPort)
  				{
***************
*** 1921,1926 **** log_line_prefix(StringInfo buf, ErrorData *edata)
--- 1981,2066 ----
  }
  
  /*
+  * Called when the GUC csvlog_fields() option has been set
+  * (currently only allowed in postmaster.conf, on PG restart).
+  *
+  * Processes the list passed in from the GUC system and updates the
+  * csvlog_field_list variable, which will then be used to generate
+  * CSV log output.
+  */
+ const char *
+ assign_csvlog_fields(const char *newval, bool doit, GucSource source)
+ {
+ 	/* Verify the list is valid */
+ 	List		*new_csv_fields = NIL;
+ 	List		*column_list = NIL;
+ 	ListCell	*l;
+ 	char		*rawstring;
+ 	MemoryContext oldcontext;
+ 
+ 	/* Need a modifyable version to pass to SplitIdentifierString */
+ 	rawstring = pstrdup(newval);
+ 
+     /* Parse string into list of identifiers */
+     if (!SplitIdentifierString(rawstring, ',', &column_list))
+ 	{
+ 		list_free(column_list);
+ 		pfree(rawstring);
+ 		return NULL;
+ 	}
+ 
+ 	/* Empty isn't a valid option */
+ 	if (column_list == NIL)
+ 	{
+ 		pfree(rawstring);
+ 		return NULL;
+ 	}
+ 
+ 	/*
+ 	 * We need the allocations done for the csvlog_field_list to
+ 	 * be preserved, so allocate them in TopMemoryContext.
+ 	 */
+ 	oldcontext = MemoryContextSwitchTo(TopMemoryContext);
+ 
+ 	/*
+ 	 * Loop through all of the fields provided by the user and build
+ 	 * up our new_csv_fields list which will be processed by write_csvlog
+ 	 */
+ 	foreach(l, column_list)
+ 	{
+ 		int curr_option;
+ 
+ 		/* Loop through all of the valid field options to try and match the
+ 		 * current entry in the list to one of them. */
+ 		for (curr_option = 0; curr_option < MAX_CSVLOG_OPTS; curr_option++)
+ 			if (pg_strcasecmp(lfirst(l),CSVFieldNames[curr_option]) == 0)
+ 			{
+ 				new_csv_fields = lappend_int(new_csv_fields,curr_option);
+ 				break;
+ 			}
+ 
+ 		/* check if no option matched, and if so, return error */
+ 		if (curr_option == MAX_CSVLOG_OPTS)
+ 			return NULL;
+ 	}
+ 
+ 	if (doit)
+ 	{
+ 		/* put new list in place */
+ 		List *old_list = csvlog_field_list;
+ 
+ 		csvlog_field_list = new_csv_fields;
+ 
+ 		list_free(old_list);
+ 	}
+ 
+ 	/* Switch back to the calling context */
+ 	MemoryContextSwitchTo(oldcontext);
+ 
+ 	return newval;
+ }
+ 
+ /*
   * append a CSV'd version of a string to a StringInfo
   * We use the PostgreSQL defaults for CSV, i.e. quote = escape = '"'
   * If it's NULL, append nothing.
***************
*** 1946,1957 **** appendCSVLiteral(StringInfo buf, const char *data)
  }
  
  /*
!  * Constructs the error message, depending on the Errordata it gets, in a CSV
!  * format which is described in doc/src/sgml/config.sgml.
   */
  static void
  write_csvlog(ErrorData *edata)
  {
  	StringInfoData buf;
  	bool		print_stmt = false;
  
--- 2086,2099 ----
  }
  
  /*
!  * Constructs the error message, depending on the Errordata it gets, in the CSV
!  * format requested by the user, based on the csvlog_fields GUC.
   */
  static void
  write_csvlog(ErrorData *edata)
  {
+ 	int			num_fields;
+ 	bool		first_field = true;
  	StringInfoData buf;
  	bool		print_stmt = false;
  
***************
*** 1961,1966 **** write_csvlog(ErrorData *edata)
--- 2103,2115 ----
  	/* has counter been reset in current process? */
  	static int	log_my_pid = 0;
  
+ 	ListCell	*l;
+ 
+ 	const char *session_auth = show_session_authorization();
+ 
+ 	/* csvlog_field_list should never be empty when we reach here */
+ 	Assert(csvlog_field_list != NIL);
+ 
  	/*
  	 * This is one of the few places where we'd rather not inherit a static
  	 * variable's value from the postmaster.  But since we will, reset it when
***************
*** 1977,2134 **** write_csvlog(ErrorData *edata)
  	initStringInfo(&buf);
  
  	/*
! 	 * timestamp with milliseconds
! 	 *
! 	 * Check if the timestamp is already calculated for the syslog message,
! 	 * and use it if so.  Otherwise, get the current timestamp.  This is done
! 	 * to put same timestamp in both syslog and csvlog messages.
  	 */
! 	if (formatted_log_time[0] == '\0')
! 		setup_formatted_log_time();
  
! 	appendStringInfoString(&buf, formatted_log_time);
! 	appendStringInfoChar(&buf, ',');
  
! 	/* username */
! 	if (MyProcPort)
! 		appendCSVLiteral(&buf, MyProcPort->user_name);
! 	appendStringInfoChar(&buf, ',');
  
! 	/* database name */
! 	if (MyProcPort)
! 		appendCSVLiteral(&buf, MyProcPort->database_name);
! 	appendStringInfoChar(&buf, ',');
  
! 	/* Process id  */
! 	if (MyProcPid != 0)
! 		appendStringInfo(&buf, "%d", MyProcPid);
! 	appendStringInfoChar(&buf, ',');
  
! 	/* Remote host and port */
! 	if (MyProcPort && MyProcPort->remote_host)
! 	{
! 		appendStringInfoChar(&buf, '"');
! 		appendStringInfoString(&buf, MyProcPort->remote_host);
! 		if (MyProcPort->remote_port && MyProcPort->remote_port[0] != '\0')
! 		{
! 			appendStringInfoChar(&buf, ':');
! 			appendStringInfoString(&buf, MyProcPort->remote_port);
! 		}
! 		appendStringInfoChar(&buf, '"');
! 	}
! 	appendStringInfoChar(&buf, ',');
  
! 	/* session id */
! 	appendStringInfo(&buf, "%lx.%x", (long) MyStartTime, MyProcPid);
! 	appendStringInfoChar(&buf, ',');
  
! 	/* Line number */
! 	appendStringInfo(&buf, "%ld", log_line_number);
! 	appendStringInfoChar(&buf, ',');
  
! 	/* PS display */
! 	if (MyProcPort)
! 	{
! 		StringInfoData msgbuf;
! 		const char *psdisp;
! 		int			displen;
  
! 		initStringInfo(&msgbuf);
  
! 		psdisp = get_ps_display(&displen);
! 		appendBinaryStringInfo(&msgbuf, psdisp, displen);
! 		appendCSVLiteral(&buf, msgbuf.data);
  
! 		pfree(msgbuf.data);
! 	}
! 	appendStringInfoChar(&buf, ',');
  
! 	/* session start timestamp */
! 	if (formatted_start_time[0] == '\0')
! 		setup_formatted_start_time();
! 	appendStringInfoString(&buf, formatted_start_time);
! 	appendStringInfoChar(&buf, ',');
  
! 	/* Virtual transaction id */
! 	/* keep VXID format in sync with lockfuncs.c */
! 	if (MyProc != NULL && MyProc->backendId != InvalidBackendId)
! 		appendStringInfo(&buf, "%d/%u", MyProc->backendId, MyProc->lxid);
! 	appendStringInfoChar(&buf, ',');
  
! 	/* Transaction id */
! 	appendStringInfo(&buf, "%u", GetTopTransactionIdIfAny());
! 	appendStringInfoChar(&buf, ',');
  
! 	/* Error severity */
! 	appendStringInfoString(&buf, error_severity(edata->elevel));
! 	appendStringInfoChar(&buf, ',');
  
! 	/* SQL state code */
! 	appendStringInfoString(&buf, unpack_sql_state(edata->sqlerrcode));
! 	appendStringInfoChar(&buf, ',');
  
! 	/* errmessage */
! 	appendCSVLiteral(&buf, edata->message);
! 	appendStringInfoChar(&buf, ',');
  
! 	/* errdetail or errdetail_log */
! 	if (edata->detail_log)
! 		appendCSVLiteral(&buf, edata->detail_log);
! 	else
! 		appendCSVLiteral(&buf, edata->detail);
! 	appendStringInfoChar(&buf, ',');
  
! 	/* errhint */
! 	appendCSVLiteral(&buf, edata->hint);
! 	appendStringInfoChar(&buf, ',');
  
! 	/* internal query */
! 	appendCSVLiteral(&buf, edata->internalquery);
! 	appendStringInfoChar(&buf, ',');
  
! 	/* if printed internal query, print internal pos too */
! 	if (edata->internalpos > 0 && edata->internalquery != NULL)
! 		appendStringInfo(&buf, "%d", edata->internalpos);
! 	appendStringInfoChar(&buf, ',');
  
! 	/* errcontext */
! 	appendCSVLiteral(&buf, edata->context);
! 	appendStringInfoChar(&buf, ',');
  
! 	/* user query --- only reported if not disabled by the caller */
! 	if (is_log_level_output(edata->elevel, log_min_error_statement) &&
! 		debug_query_string != NULL &&
! 		!edata->hide_stmt)
! 		print_stmt = true;
! 	if (print_stmt)
! 		appendCSVLiteral(&buf, debug_query_string);
! 	appendStringInfoChar(&buf, ',');
! 	if (print_stmt && edata->cursorpos > 0)
! 		appendStringInfo(&buf, "%d", edata->cursorpos);
! 	appendStringInfoChar(&buf, ',');
! 
! 	/* file error location */
! 	if (Log_error_verbosity >= PGERROR_VERBOSE)
! 	{
! 		StringInfoData msgbuf;
! 
! 		initStringInfo(&msgbuf);
! 
! 		if (edata->funcname && edata->filename)
! 			appendStringInfo(&msgbuf, "%s, %s:%d",
! 							 edata->funcname, edata->filename,
! 							 edata->lineno);
! 		else if (edata->filename)
! 			appendStringInfo(&msgbuf, "%s:%d",
! 							 edata->filename, edata->lineno);
! 		appendCSVLiteral(&buf, msgbuf.data);
! 		pfree(msgbuf.data);
! 	}
! 	appendStringInfoChar(&buf, ',');
  
! 	/* application name */
! 	if (application_name)
! 		appendCSVLiteral(&buf, application_name);
  
  	appendStringInfoChar(&buf, '\n');
  
--- 2126,2374 ----
  	initStringInfo(&buf);
  
  	/*
! 	 * Get the number of fields, so we make sure to *not* include a comma
! 	 * after the last field.
  	 */
! 	num_fields = list_length(csvlog_field_list);
  
! 	/*
! 	 * Loop through the fields requested by the user, in the order requested, in
! 	 * the csvlog_fields GUC.
! 	 */
! 	foreach(l, csvlog_field_list)
! 	{
! 		/* If this isn't the first field, prepend a comma to seperate this
! 		 * field from the previous one */
! 		if (!first_field)
! 			appendStringInfoChar(&buf, ',');
! 		else
! 			first_field = false;
  
! 		switch (lfirst_int(l))
! 		{
! 			case CSVLOG_LOG_TIME:
! 				{
! 					/*
! 					 * timestamp with milliseconds
! 					 *
! 					 * Check if the timestamp is already calculated for the syslog message,
! 					 * and use it if so.  Otherwise, get the current timestamp.  This is done
! 					 * to put same timestamp in both syslog and csvlog messages.
! 					 */
! 					if (formatted_log_time[0] == '\0')
! 						setup_formatted_log_time();
! 
! 					appendStringInfoString(&buf, formatted_log_time);
! 				}
! 				break;
  
! 			case CSVLOG_USER_NAME:
! 				{
! 					/* session username, as done for %u */
! 					if (*session_auth != '\0')
! 						appendCSVLiteral(&buf, session_auth);
! 					else
! 						/* username */
! 						if (MyProcPort)
! 						{
! 							const char *username = MyProcPort->user_name;
! 							if (username == NULL || *username == '\0')
! 								username = _("[unknown]");
! 							appendCSVLiteral(&buf, MyProcPort->user_name);
! 						}
! 				}
! 				break;
  
! 			case CSVLOG_ROLE_NAME:
! 				/* current role, not updated if someone renames it in another
! 				 * session, of course */
! 				appendCSVLiteral(&buf, show_role());
! 				break;
  
! 			case CSVLOG_DATABASE_NAME:
! 				{
! 					/* database name */
! 					if (MyProcPort)
! 						appendCSVLiteral(&buf, MyProcPort->database_name);
! 				}
! 				break;
  
! 			case CSVLOG_PROCESS_ID:
! 				{
! 					/* Process id  */
! 					if (MyProcPid != 0)
! 						appendStringInfo(&buf, "%d", MyProcPid);
! 				}
! 				break;
  
! 			case CSVLOG_CONNECTION_FROM:
! 				{
! 					/* Remote host and port */
! 					if (MyProcPort && MyProcPort->remote_host)
! 					{
! 						appendStringInfoChar(&buf, '"');
! 						appendStringInfoString(&buf, MyProcPort->remote_host);
! 						if (MyProcPort->remote_port && MyProcPort->remote_port[0] != '\0')
! 						{
! 							appendStringInfoChar(&buf, ':');
! 							appendStringInfoString(&buf, MyProcPort->remote_port);
! 						}
! 						appendStringInfoChar(&buf, '"');
! 					}
! 				}
! 				break;
  
! 			case CSVLOG_SESSION_ID:
! 				/* session id */
! 				appendStringInfo(&buf, "%lx.%x", (long) MyStartTime, MyProcPid);
! 				break;
  
! 			case CSVLOG_SESSION_LINE_NUM:
! 				/* Line number */
! 				appendStringInfo(&buf, "%ld", log_line_number);
! 				break;
  
! 			case CSVLOG_COMMAND_TAG:
! 				{
! 					/* PS display */
! 					if (MyProcPort)
! 					{
! 						StringInfoData msgbuf;
! 						const char *psdisp;
! 						int			displen;
  
! 						initStringInfo(&msgbuf);
  
! 						psdisp = get_ps_display(&displen);
! 						appendBinaryStringInfo(&msgbuf, psdisp, displen);
! 						appendCSVLiteral(&buf, msgbuf.data);
  
! 						pfree(msgbuf.data);
! 					}
! 				}
! 				break;
  
! 			case CSVLOG_SESSION_START_TIME:
! 				{
! 					/* session start timestamp */
! 					if (formatted_start_time[0] == '\0')
! 						setup_formatted_start_time();
! 					appendStringInfoString(&buf, formatted_start_time);
! 				}
! 				break;
  
! 			case CSVLOG_VIRTUAL_TRANSACTION_ID:
! 				{
! 					/* Virtual transaction id */
! 					/* keep VXID format in sync with lockfuncs.c */
! 					if (MyProc != NULL && MyProc->backendId != InvalidBackendId)
! 						appendStringInfo(&buf, "%d/%u", MyProc->backendId, MyProc->lxid);
! 				}
! 				break;
  
! 			case CSVLOG_TRANSACTION_ID:
! 				/* Transaction id */
! 				appendStringInfo(&buf, "%u", GetTopTransactionIdIfAny());
! 				break;
  
! 			case CSVLOG_ERROR_SEVERITY:
! 				/* Error severity */
! 				appendStringInfoString(&buf, error_severity(edata->elevel));
! 				break;
  
! 			case CSVLOG_SQL_STATE_CODE:
! 				/* SQL state code */
! 				appendStringInfoString(&buf, unpack_sql_state(edata->sqlerrcode));
! 				break;
! 
! 			case CSVLOG_MESSAGE:
! 				/* errmessage */
! 				appendCSVLiteral(&buf, edata->message);
! 				break;
! 
! 			case CSVLOG_DETAIL:
! 				{
! 					/* errdetail or errdetail_log */
! 					if (edata->detail_log)
! 						appendCSVLiteral(&buf, edata->detail_log);
! 					else
! 						appendCSVLiteral(&buf, edata->detail);
! 				}
! 				break;
  
! 			case CSVLOG_HINT:
! 				/* errhint */
! 				appendCSVLiteral(&buf, edata->hint);
! 				break;
  
! 			case CSVLOG_INTERNAL_QUERY:
! 				/* internal query */
! 				appendCSVLiteral(&buf, edata->internalquery);
! 				break;
  
! 			case CSVLOG_INTERNAL_QUERY_POS:
! 				{
! 					/* if printed internal query, print internal pos too */
! 					if (edata->internalpos > 0 && edata->internalquery != NULL)
! 						appendStringInfo(&buf, "%d", edata->internalpos);
! 				}
! 				break;
  
! 			case CSVLOG_CONTEXT:
! 				/* errcontext */
! 				appendCSVLiteral(&buf, edata->context);
! 				break;
  
! 			case CSVLOG_QUERY:
! 				{
! 					/* user query --- only reported if not disabled by the caller */
! 					if (is_log_level_output(edata->elevel, log_min_error_statement) &&
! 						debug_query_string != NULL &&
! 						!edata->hide_stmt)
! 						print_stmt = true;
! 					if (print_stmt)
! 						appendCSVLiteral(&buf, debug_query_string);
! 				}
! 				break;
! 
! 			case CSVLOG_QUERY_POS:
! 				{
! 					if (print_stmt && edata->cursorpos > 0)
! 						appendStringInfo(&buf, "%d", edata->cursorpos);
! 				}
! 				break;
  
! 			case CSVLOG_LOCATION:
! 				{
! 					/* file error location */
! 					if (Log_error_verbosity >= PGERROR_VERBOSE)
! 					{
! 						StringInfoData msgbuf;
! 
! 						initStringInfo(&msgbuf);
! 
! 						if (edata->funcname && edata->filename)
! 							appendStringInfo(&msgbuf, "%s, %s:%d",
! 											 edata->funcname, edata->filename,
! 											 edata->lineno);
! 						else if (edata->filename)
! 							appendStringInfo(&msgbuf, "%s:%d",
! 											 edata->filename, edata->lineno);
! 						appendCSVLiteral(&buf, msgbuf.data);
! 						pfree(msgbuf.data);
! 					}
! 				}
! 				break;
! 
! 			case CSVLOG_APPLICATION_NAME:
! 				{
! 					/* application name */
! 					if (application_name)
! 						appendCSVLiteral(&buf, application_name);
! 				}
! 				break;
! 		}
! 	}
  
  	appendStringInfoChar(&buf, '\n');
  
***************
*** 2139,2144 **** write_csvlog(ErrorData *edata)
--- 2379,2386 ----
  		write_pipe_chunks(buf.data, buf.len, LOG_DESTINATION_CSVLOG);
  
  	pfree(buf.data);
+ 
+ 	return;
  }
  
  /*
*** a/src/backend/utils/misc/guc.c
--- b/src/backend/utils/misc/guc.c
***************
*** 65,70 ****
--- 65,71 ----
  #include "tsearch/ts_cache.h"
  #include "utils/builtins.h"
  #include "utils/bytea.h"
+ #include "utils/elog.h"
  #include "utils/guc_tables.h"
  #include "utils/memutils.h"
  #include "utils/pg_locale.h"
***************
*** 191,196 **** static char *config_enum_get_options(struct config_enum * record,
--- 192,200 ----
  						const char *prefix, const char *suffix,
  						const char *separator);
  
+ /* Needs to be defined here because elog.h can't #include guc.h */
+ extern const char *assign_csvlog_fields(const char *newval,
+                 bool doit, GucSource source);
  
  /*
   * Options for enum values defined in this module.
***************
*** 1034,1039 **** static struct config_bool ConfigureNamesBool[] =
--- 1038,1052 ----
  		false, NULL, NULL
  	},
  	{
+ 		{"csvlog_header", PGC_POSTMASTER, LOGGING_WHAT,
+ 			gettext_noop("Enables including a header on CSV log files."),
+ 			NULL,
+ 		},
+ 		&csvlog_header,
+ 		false, NULL, NULL
+ 	},
+ 
+ 	{
  		{"sql_inheritance", PGC_USERSET, COMPAT_OPTIONS_PREVIOUS,
  			gettext_noop("Causes subtables to be included by default in various commands."),
  			NULL
***************
*** 2326,2331 **** static struct config_string ConfigureNamesString[] =
--- 2339,2355 ----
  	},
  
  	{
+ 		{"csvlog_fields", PGC_POSTMASTER, LOGGING_WHAT,
+ 			gettext_noop("Controls fields logged to CSV logfiles."),
+ 			gettext_noop("If blank, the default set of fields is used."),
+ 			GUC_LIST_INPUT
+ 		},
+ 		&csvlog_fields,
+ 		"log_time, user_name, database_name, process_id, connection_from, session_id, session_line_num, command_tag, session_start_time, virtual_transaction_id, transaction_id, error_severity, sql_state_code, message, detail, hint, internal_query, internal_query_pos, context, query, query_pos, location, application_name",
+ 		assign_csvlog_fields, NULL
+ 	},
+ 
+ 	{
  		{"log_timezone", PGC_SIGHUP, LOGGING_WHAT,
  			gettext_noop("Sets the time zone to use in log messages."),
  			NULL
*** a/src/backend/utils/misc/postgresql.conf.sample
--- b/src/backend/utils/misc/postgresql.conf.sample
***************
*** 378,383 ****
--- 378,388 ----
  					#        processes
  					#   %% = '%'
  					# e.g. '<%u%%%d> '
+ 
+ # fields to include in the CSV log output
+ #csvlog_fields = 'log_time, user_name, database_name, process_id, connection_from, session_id, session_line_num, command_tag, session_start_time, virtual_transaction_id, transaction_id, error_severity, sql_state_code, message, detail, hint, internal_query, internal_query_pos, context, query, query_pos, location, application_name'
+ #csvlog_header = false			# should csvlog files have a header?
+ 
  #log_lock_waits = off			# log lock waits >= deadlock_timeout
  #log_statement = 'none'			# none, ddl, mod, all
  #log_temp_files = -1			# log temporary files equal or larger
*** a/src/include/utils/elog.h
--- b/src/include/utils/elog.h
***************
*** 330,337 **** typedef enum
--- 330,386 ----
  
  extern int	Log_error_verbosity;
  extern char *Log_line_prefix;
+ extern char *csvlog_fields; /* List of fields to log with CSV logging */
+ extern bool	csvlog_header; /* Whether to include a header on CSV log files */
  extern int	Log_destination;
  
+ /*
+  * Enum of the CSV fields we understand for CSV-based logging,
+  * if an new field is added, the enum has to be updated, the
+  * definition of field names in elog.c needs to be updated, and the
+  * new field needs to be handled in write_csv() in elog.c.
+  * Also be sure to update MAX_CSVLOG_OPTS if you change what the last
+  * option in the enum list is.
+  */
+ typedef enum LogCSVFields
+ {
+ 	CSVLOG_LOG_TIME,
+ 	CSVLOG_USER_NAME,
+ 	CSVLOG_ROLE_NAME,
+ 	CSVLOG_DATABASE_NAME,
+ 	CSVLOG_PROCESS_ID,
+ 	CSVLOG_CONNECTION_FROM,
+ 	CSVLOG_SESSION_ID,
+ 	CSVLOG_SESSION_LINE_NUM,
+ 	CSVLOG_COMMAND_TAG,
+ 	CSVLOG_SESSION_START_TIME,
+ 	CSVLOG_VIRTUAL_TRANSACTION_ID,
+ 	CSVLOG_TRANSACTION_ID,
+ 	CSVLOG_ERROR_SEVERITY,
+ 	CSVLOG_SQL_STATE_CODE,
+ 	CSVLOG_MESSAGE,
+ 	CSVLOG_DETAIL,
+ 	CSVLOG_HINT,
+ 	CSVLOG_INTERNAL_QUERY,
+ 	CSVLOG_INTERNAL_QUERY_POS,
+ 	CSVLOG_CONTEXT,
+ 	CSVLOG_QUERY,
+ 	CSVLOG_QUERY_POS,
+ 	CSVLOG_LOCATION,
+ 	CSVLOG_APPLICATION_NAME
+ } LogCSVFields;
+ 
+ /* Make sure to update this if you add CSV log options and change
+  * what the last CSVLOG option is */
+ #define MAX_CSVLOG_OPTS CSVLOG_APPLICATION_NAME+1
+ 
+ /*
+  * Array of the names of each of the CSV fields we allow for logging,
+  * if an new field is added, the enum has to be updated *and* the
+  * definition of field names in elog.c needs to be updated.
+  */
+ extern const char *CSVFieldNames[];
+ 
  /* Log destination bitmap */
  #define LOG_DESTINATION_STDERR	 1
  #define LOG_DESTINATION_SYSLOG	 2
*** a/src/tools/pgindent/typedefs.list
--- b/src/tools/pgindent/typedefs.list
***************
*** 855,860 **** LockTagType
--- 855,861 ----
  LockTupleMode
  LockingClause
  LogStmtLevel
+ LogCSVFields
  LogicalTape
  LogicalTapeSet
  MAGIC

*** a/doc/src/sgml/config.sgml
--- b/doc/src/sgml/config.sgml
***************
*** 3542,3548 **** local0.*    /var/log/postgresql
              </row>
              <row>
               <entry><literal>%u</literal></entry>
!              <entry>User name</entry>
               <entry>yes</entry>
              </row>
              <row>
--- 3542,3561 ----
              </row>
              <row>
               <entry><literal>%u</literal></entry>
!              <entry>Session user name, typically the user name which was used
!              to authenticate to <productname>PostgreSQL</productname> with,
!              but can be changed by a superuser, see <command>SET SESSION
!              AUTHORIZATION</></entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>%U</literal></entry>
!              <entry>Current role name, when set with <command>SET ROLE</>;
!              the current role identifier is relevant for permission checking;
!              Returns 'none' if the current role matches the session user.
!              Note: Log messages from inside <literal>SECURITY DEFINER</>
!              functions will show the calling role, not the effective role
!              inside the <literal>SECURITY DEFINER</> function</entry>
               <entry>yes</entry>
              </row>
              <row>
***************
*** 3659,3664 **** FROM pg_stat_activity;
--- 3672,3717 ----
        </listitem>
       </varlistentry>
  
+      <varlistentry id="guc-csvlog-fields" xreflabel="csvlog_fields">
+       <term><varname>csvlog_fields</varname> (<type>string</type>)</term>
+       <indexterm>
+        <primary><varname>csvlog_fields</> configuration parameter</primary>
+       </indexterm>
+       <listitem>
+        <para>
+         Controls the set and order of the fields which are written out in
+         the CSV-format log file.
+ 
+         The default is:
+         <literal>log_time, user_name, database_name, process_id,
+         connection_from, session_id, session_line_num, command_tag,
+         session_start_time, virtual_transaction_id, transaction_id,
+         error_severity, sql_state_code, message, detail, hint,
+         internal_query, internal_query_pos, context, query, query_pos,
+         location, application_name</literal>
+ 
+         For details on what these fields are, refer to the
+         <varname>log_line_prefix</varname> and
+         <xref linkend="runtime-config-logging-csvlog"> documentation.
+        </para>
+       </listitem>
+      </varlistentry>
+ 
+      <varlistentry id="guc-csvlog-header" xreflabel="csvlog_header">
+       <term><varname>csvlog_header</varname> (<type>boolean</type>)</term>
+       <indexterm>
+        <primary><varname>csvlog_header</> configuration parameter</primary>
+       </indexterm>
+       <listitem>
+        <para>
+         Controls if a header should be output for each file logged through
+         the CSV-format logging.
+ 
+         The default is: <literal>false</literal>, for backwards compatibility.
+        </para>
+       </listitem>
+      </varlistentry>
+ 
       <varlistentry id="guc-log-lock-waits" xreflabel="log_lock_waits">
        <term><varname>log_lock_waits</varname> (<type>boolean</type>)</term>
        <indexterm>
***************
*** 3766,3799 **** FROM pg_stat_activity;
          Including <literal>csvlog</> in the <varname>log_destination</> list
          provides a convenient way to import log files into a database table.
          This option emits log lines in comma-separated-values
!         (<acronym>CSV</>) format,
!         with these columns:
!         timestamp with milliseconds,
!         user name,
!         database name,
!         process ID,
!         client host:port number,
!         session ID,
!         per-session line number,
!         command tag,
!         session start time,
!         virtual transaction ID,
!         regular transaction ID,
!         error severity,
!         SQLSTATE code,
!         error message,
!         error message detail,
!         hint,
!         internal query that led to the error (if any),
!         character count of the error position therein,
!         error context,
!         user query that led to the error (if any and enabled by
!         <varname>log_min_error_statement</>),
!         character count of the error position therein,
!         location of the error in the PostgreSQL source code
!         (if <varname>log_error_verbosity</> is set to <literal>verbose</>),
!         and application name.
!         Here is a sample table definition for storing CSV-format log output:
  
  <programlisting>
  CREATE TABLE postgres_log
--- 3819,3971 ----
          Including <literal>csvlog</> in the <varname>log_destination</> list
          provides a convenient way to import log files into a database table.
          This option emits log lines in comma-separated-values
!         (<acronym>CSV</>) format.  The following table defines the fields
!         which can be included in the CSV output, their meanings, and if they
!         are included in the default CSV layout (the default ordering matches
!         the order of this table).
! 
!          <informaltable>
!           <tgroup cols="3">
!            <thead>
!             <row>
!              <entry>CSV Field Name</entry>
!              <entry>Definition</entry>
!              <entry>Included by Default</entry>
!              </row>
!             </thead>
!            <tbody>
!             <row>
!              <entry><literal>log_time</literal></entry>
!              <entry>timestamp with milliseconds</entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>user_name</literal></entry>
!              <entry>session user name</entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>role_name</literal></entry>
!              <entry>current role name</entry>
!              <entry>no</entry>
!             </row>
!             <row>
!              <entry><literal>database_name</literal></entry>
!              <entry>name of database connected to</entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>process_id</literal></entry>
!              <entry>process ID of the backend PG process</entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>connection_from</literal></entry>
!              <entry>client host/IP and port number</entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>session_id</literal></entry>
!              <entry>ID of the session</entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>session_line_number</literal></entry>
!              <entry>per-session line number</entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>command_tag</literal></entry>
!              <entry>Command tag of the logged command</entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>session_start_time</literal></entry>
!              <entry>Start time of the current session</entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>virtual_transaction_id</literal></entry>
!              <entry>Virtual Transaction ID</entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>transaction_id</literal></entry>
!              <entry>Regular Transaction ID</entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>error_severity</literal></entry>
!              <entry>Error severity code of the log message</entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>sql_state_code</literal></entry>
!              <entry>SQLSTATE code of the command being logged</entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>message</literal></entry>
!              <entry>Error message</entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>detail</literal></entry>
!              <entry>Error message detail</entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>hint</literal></entry>
!              <entry>Error message hint</entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>internal_query</literal></entry>
!              <entry>internal query that led to the error (if any)</entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>internal_query_pos</literal></entry>
!              <entry>character count of the error position of the internal query</entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>context</literal></entry>
!              <entry>error context</entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>query</literal></entry>
!              <entry>user query that led to the error (if any and enabled by <varname>log_min_error_statement</varname>)</entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>query_pos</literal></entry>
!              <entry>character count of the error position of the user query</entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>location</literal></entry>
!              <entry>location of the error in the PostgreSQL source code (if <varname>log_error_verbosity</varname> is set to <literal>verbose</literal>)</entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>application_name</literal></entry>
!              <entry>Name of the connecting application, if provided by the application</entry>
!              <entry>yes</entry>
!             </row>
!            </tbody>
!           </tgroup>
!          </informaltable>
! 
!         The set of columns to be included, and their order, in the CSV
!         output can be controlled using the <varname>csvlog_fields</varname> option.
! 
!         For additional details on the definition of the above columns, refer
!         to the documentation for <varname>log_line_prefix</varname>.
! 
!         Here is a sample table definition for storing the default CSV-format
!         log output:
  
  <programlisting>
  CREATE TABLE postgres_log
*** a/src/backend/commands/variable.c
--- b/src/backend/commands/variable.c
***************
*** 847,852 **** assign_session_authorization(const char *value, bool doit, GucSource source)
--- 847,857 ----
  	return result;
  }
  
+ /*
+  * function to return the stored session username, needed because we
+  * can't do catalog lookups when possibly being called after an error,
+  * eg: from elog.c or part of GUC handling.
+  */
  const char *
  show_session_authorization(void)
  {
***************
*** 972,977 **** assign_role(const char *value, bool doit, GucSource source)
--- 977,987 ----
  	return result;
  }
  
+ /*
+  * function to return the stored role username, needed because we
+  * can't do catalog lookups when possibly being called after an error,
+  * eg: from elog.c or part of GUC handling.
+  */
  const char *
  show_role(void)
  {
*** a/src/backend/postmaster/syslogger.c
--- b/src/backend/postmaster/syslogger.c
***************
*** 147,152 **** static char *logfile_getname(pg_time_t timestamp, const char *suffix);
--- 147,153 ----
  static void set_next_rotation_time(void);
  static void sigHupHandler(SIGNAL_ARGS);
  static void sigUsr1Handler(SIGNAL_ARGS);
+ static void write_csvlog_header(FILE *out_fh);
  
  
  /*
***************
*** 988,993 **** pipeThread(void *arg)
--- 989,1019 ----
  #endif   /* WIN32 */
  
  /*
+  * Internal function for writing out the header of a CSV-style log file
+  * to the passed-in file handle.
+  */
+ static void
+ write_csvlog_header(FILE *out_fh)
+ {
+ 	int				rc;
+ 	int				header_length = strlen(csvlog_fields);
+ 
+ 	/* Write out the csvlog_fields GUC, which matches the CSV log format
+ 	 * header, at least, if we did everything right. */
+ 	rc = fwrite(csvlog_fields, 1, header_length, out_fh);
+ 
+ 	/* can't use ereport here because of possible recursion */
+ 	if (rc != header_length)
+ 		write_stderr("could not write to new log file: %s\n", strerror(errno));
+ 
+ 	rc = fputc('\n', out_fh);
+ 	if (rc != '\n')
+ 		write_stderr("could not write to new log file: %s\n", strerror(errno));
+ 
+ 	return;
+ }
+ 
+ /*
   * open the csv log file - we do this opportunistically, because
   * we don't know if CSV logging will be wanted.
   */
***************
*** 995,1004 **** static void
  open_csvlogfile(void)
  {
  	char	   *filename;
  
  	filename = logfile_getname(time(NULL), ".csv");
  
! 	csvlogFile = logfile_open(filename, "a", false);
  
  	pfree(filename);
  }
--- 1021,1037 ----
  open_csvlogfile(void)
  {
  	char	   *filename;
+ 	FILE	   *fh;
  
  	filename = logfile_getname(time(NULL), ".csv");
  
! 	fh = logfile_open(filename, "a", false);
! 
! 	/* Check if we are asked to write out a header for the CSV file. */
! 	if (csvlog_header)
! 		write_csvlog_header(fh);
! 
! 	csvlogFile = fh;
  
  	pfree(filename);
  }
***************
*** 1165,1170 **** logfile_rotate(bool time_based_rotation, int size_rotation_for)
--- 1198,1207 ----
  			return;
  		}
  
+ 		/* Check if we are asked to write out a header for the CSV file. */
+ 		if (csvlog_header)
+ 			write_csvlog_header(fh);
+ 
  		fclose(csvlogFile);
  		csvlogFile = fh;
  
*** a/src/backend/utils/error/elog.c
--- b/src/backend/utils/error/elog.c
***************
*** 3,8 ****
--- 3,17 ----
   * elog.c
   *	  error logging and reporting
   *
+  * A few comments about situations where error processing is called:
+  *
+  * We need to be cautious of both a performance hit when logging, since
+  * log messages can be generated at a huge rate if every command is being
+  * logged and we also need to watch out for what can happen when we are
+  * trying to log from an aborted transaction.  Specifically, attempting to
+  * do SysCache lookups and possibly use other usually available backend
+  * systems will fail badly when logging from an aborted transaction.
+  *
   * Some notes about recursion and errors during error processing:
   *
   * We need to be robust about recursive-error scenarios --- for example,
***************
*** 59,73 ****
--- 68,85 ----
  
  #include "access/transam.h"
  #include "access/xact.h"
+ #include "commands/variable.h"
  #include "libpq/libpq.h"
  #include "libpq/pqformat.h"
  #include "mb/pg_wchar.h"
  #include "miscadmin.h"
+ #include "nodes/pg_list.h"
  #include "postmaster/postmaster.h"
  #include "postmaster/syslogger.h"
  #include "storage/ipc.h"
  #include "storage/proc.h"
  #include "tcop/tcopprot.h"
+ #include "utils/builtins.h"
  #include "utils/guc.h"
  #include "utils/memutils.h"
  #include "utils/ps_status.h"
***************
*** 93,98 **** extern bool redirection_done;
--- 105,144 ----
  int			Log_error_verbosity = PGERROR_VERBOSE;
  char	   *Log_line_prefix = NULL;		/* format for extra log line info */
  int			Log_destination = LOG_DESTINATION_STDERR;
+ char	   *csvlog_fields = NULL;
+ bool		csvlog_header = false;
+ 
+ static List *csvlog_field_list = NIL;
+ 
+ /* To add a CSV field option, you need to update the enum in elog.h, check
+  * if the last value in the enum changed and if so update MAX_CSVLOG_OPTS,
+  * add code to handle the option in write_csv(), and add it here. */
+ const char *CSVFieldNames[] = {
+ 	"log_time",					/* CSVLOG_LOG_TIME */
+ 	"user_name",				/* CSVLOG_USER_NAME */
+ 	"role_name",				/* CSVLOG_ROLE_NAME */
+ 	"database_name",			/* CSVLOG_DATABASE_NAME */
+ 	"process_id",				/* CSVLOG_PROCESS_ID */
+ 	"connection_from",			/* CSVLOG_CONNECTION_FROM */
+ 	"session_id",				/* CSVLOG_SESSION_ID */
+ 	"session_line_num",			/* CSVLOG_SESSION_LINE_NUM */
+ 	"command_tag",				/* CSVLOG_COMMAND_TAG */
+ 	"session_start_time",		/* CSVLOG_SESSION_START_TIME */
+ 	"virtual_transaction_id",	/* CSVLOG_VIRTUAL_TRANSACTION_ID */
+ 	"transaction_id",			/* CSVLOG_TRANSACTION_ID */
+ 	"error_severity",			/* CSVLOG_ERROR_SEVERITY */
+ 	"sql_state_code",			/* CSVLOG_SQL_STATE_CODE */
+ 	"message",					/* CSVLOG_MESSAGE */
+ 	"detail",					/* CSVLOG_DETAIL */
+ 	"hint",						/* CSVLOG_HINT */
+ 	"internal_query",			/* CSVLOG_INTERNAL_QUERY */
+ 	"internal_query_pos",		/* CSVLOG_INTERNAL_QUERY_POS */
+ 	"context",					/* CSVLOG_CONTEXT */
+ 	"query",					/* CSVLOG_QUERY */
+ 	"query_pos",				/* CSVLOG_QUERY_POS */
+ 	"location",					/* CSVLOG_LOCATION */
+ 	"application_name"			/* CSVLOG_APPLICATION_NAME */
+ };
  
  #ifdef HAVE_SYSLOG
  
***************
*** 161,166 **** static void write_csvlog(ErrorData *edata);
--- 207,217 ----
  static void setup_formatted_log_time(void);
  static void setup_formatted_start_time(void);
  
+ /* extern'd and used from guc.c... */
+ const char *assign_csvlog_fields(const char *newval, bool doit,
+ 								 GucSource source);
+ 
+ 
  
  /*
   * in_error_recursion_trouble --- are we at risk of infinite error recursion?
***************
*** 1817,1831 **** log_line_prefix(StringInfo buf, ErrorData *edata)
  				}
  				break;
  			case 'u':
- 				if (MyProcPort)
  				{
! 					const char *username = MyProcPort->user_name;
! 
! 					if (username == NULL || *username == '\0')
! 						username = _("[unknown]");
! 					appendStringInfoString(buf, username);
  				}
  				break;
  			case 'd':
  				if (MyProcPort)
  				{
--- 1868,1891 ----
  				}
  				break;
  			case 'u':
  				{
! 					const char *session_auth = show_session_authorization();
! 
! 					if (*session_auth != '\0')
! 						appendStringInfoString(buf, session_auth);
! 					else if (MyProcPort)
! 					{
! 						const char *username = MyProcPort->user_name;
! 
! 						if (username == NULL || *username == '\0')
! 							username = _("[unknown]");
! 						appendStringInfoString(buf, username);
! 					}
  				}
  				break;
+ 			case 'U':
+ 				appendStringInfoString(buf, show_role());
+ 				break;
  			case 'd':
  				if (MyProcPort)
  				{
***************
*** 1921,1926 **** log_line_prefix(StringInfo buf, ErrorData *edata)
--- 1981,2073 ----
  }
  
  /*
+  * Called when the GUC csvlog_fields() option has been set
+  * (currently only allowed in postmaster.conf, on PG restart).
+  *
+  * Processes the list passed in from the GUC system and updates the
+  * csvlog_field_list variable, which will then be used to generate
+  * CSV log output.
+  */
+ const char *
+ assign_csvlog_fields(const char *newval, bool doit, GucSource source)
+ {
+ 	/* Verify the list is valid */
+ 	List		*new_csv_fields = NIL;		/* List we're building */
+ 	List		*column_list = NIL;			/* List of columns from user */
+ 	ListCell	*l;
+ 	char		*rawstring;					/* Copy of user string */
+ 	MemoryContext oldcontext;
+ 
+ 	/* Need a modifyable version to pass to SplitIdentifierString */
+ 	rawstring = pstrdup(newval);
+ 
+     /* Parse string into list of identifiers */
+     if (!SplitIdentifierString(rawstring, ',', &column_list))
+ 	{
+ 		list_free(column_list);
+ 		pfree(rawstring);
+ 		return NULL;
+ 	}
+ 
+ 	/* Empty isn't a valid option */
+ 	if (column_list == NIL)
+ 	{
+ 		pfree(rawstring);
+ 		return NULL;
+ 	}
+ 
+ 	/*
+ 	 * We need the allocations done for the csvlog_field_list to
+ 	 * be preserved, so allocate them in TopMemoryContext.
+ 	 */
+ 	oldcontext = MemoryContextSwitchTo(TopMemoryContext);
+ 
+ 	/*
+ 	 * Loop through all of the fields provided by the user and build
+ 	 * up our new_csv_fields list which will be processed by write_csvlog
+ 	 */
+ 	foreach(l, column_list)
+ 	{
+ 		int curr_option;
+ 
+ 		/* Loop through all of the valid field options to try and match the
+ 		 * current entry in the list to one of them. */
+ 		for (curr_option = 0; curr_option < MAX_CSVLOG_OPTS; curr_option++)
+ 			if (pg_strcasecmp(lfirst(l),CSVFieldNames[curr_option]) == 0)
+ 			{
+ 				new_csv_fields = lappend_int(new_csv_fields,curr_option);
+ 				break;
+ 			}
+ 
+ 		/* check if no option matched, and if so, return error */
+ 		if (curr_option == MAX_CSVLOG_OPTS)
+ 		{
+ 			list_free(column_list);
+ 			pfree(rawstring);
+ 			return NULL;
+ 		}
+ 	}
+ 
+ 	if (doit)
+ 	{
+ 		/* put new list in place */
+ 		List *old_list = csvlog_field_list;
+ 
+ 		csvlog_field_list = new_csv_fields;
+ 
+ 		list_free(old_list);
+ 	}
+ 
+ 	list_free(column_list);
+ 	pfree(rawstring);
+ 
+ 	/* Switch back to the calling context */
+ 	MemoryContextSwitchTo(oldcontext);
+ 
+ 	return newval;
+ }
+ 
+ /*
   * append a CSV'd version of a string to a StringInfo
   * We use the PostgreSQL defaults for CSV, i.e. quote = escape = '"'
   * If it's NULL, append nothing.
***************
*** 1946,1957 **** appendCSVLiteral(StringInfo buf, const char *data)
  }
  
  /*
!  * Constructs the error message, depending on the Errordata it gets, in a CSV
!  * format which is described in doc/src/sgml/config.sgml.
   */
  static void
  write_csvlog(ErrorData *edata)
  {
  	StringInfoData buf;
  	bool		print_stmt = false;
  
--- 2093,2106 ----
  }
  
  /*
!  * Constructs the error message, depending on the Errordata it gets, in the CSV
!  * format requested by the user, based on the csvlog_fields GUC.
   */
  static void
  write_csvlog(ErrorData *edata)
  {
+ 	int			num_fields;
+ 	bool		first_field = true;
  	StringInfoData buf;
  	bool		print_stmt = false;
  
***************
*** 1961,1966 **** write_csvlog(ErrorData *edata)
--- 2110,2122 ----
  	/* has counter been reset in current process? */
  	static int	log_my_pid = 0;
  
+ 	ListCell	*l;
+ 
+ 	const char *session_auth = show_session_authorization();
+ 
+ 	/* csvlog_field_list should never be empty when we reach here */
+ 	Assert(csvlog_field_list != NIL);
+ 
  	/*
  	 * This is one of the few places where we'd rather not inherit a static
  	 * variable's value from the postmaster.  But since we will, reset it when
***************
*** 1977,2134 **** write_csvlog(ErrorData *edata)
  	initStringInfo(&buf);
  
  	/*
! 	 * timestamp with milliseconds
! 	 *
! 	 * Check if the timestamp is already calculated for the syslog message,
! 	 * and use it if so.  Otherwise, get the current timestamp.  This is done
! 	 * to put same timestamp in both syslog and csvlog messages.
  	 */
! 	if (formatted_log_time[0] == '\0')
! 		setup_formatted_log_time();
  
! 	appendStringInfoString(&buf, formatted_log_time);
! 	appendStringInfoChar(&buf, ',');
  
! 	/* username */
! 	if (MyProcPort)
! 		appendCSVLiteral(&buf, MyProcPort->user_name);
! 	appendStringInfoChar(&buf, ',');
  
! 	/* database name */
! 	if (MyProcPort)
! 		appendCSVLiteral(&buf, MyProcPort->database_name);
! 	appendStringInfoChar(&buf, ',');
  
! 	/* Process id  */
! 	if (MyProcPid != 0)
! 		appendStringInfo(&buf, "%d", MyProcPid);
! 	appendStringInfoChar(&buf, ',');
  
! 	/* Remote host and port */
! 	if (MyProcPort && MyProcPort->remote_host)
! 	{
! 		appendStringInfoChar(&buf, '"');
! 		appendStringInfoString(&buf, MyProcPort->remote_host);
! 		if (MyProcPort->remote_port && MyProcPort->remote_port[0] != '\0')
! 		{
! 			appendStringInfoChar(&buf, ':');
! 			appendStringInfoString(&buf, MyProcPort->remote_port);
! 		}
! 		appendStringInfoChar(&buf, '"');
! 	}
! 	appendStringInfoChar(&buf, ',');
  
! 	/* session id */
! 	appendStringInfo(&buf, "%lx.%x", (long) MyStartTime, MyProcPid);
! 	appendStringInfoChar(&buf, ',');
  
! 	/* Line number */
! 	appendStringInfo(&buf, "%ld", log_line_number);
! 	appendStringInfoChar(&buf, ',');
  
! 	/* PS display */
! 	if (MyProcPort)
! 	{
! 		StringInfoData msgbuf;
! 		const char *psdisp;
! 		int			displen;
  
! 		initStringInfo(&msgbuf);
  
! 		psdisp = get_ps_display(&displen);
! 		appendBinaryStringInfo(&msgbuf, psdisp, displen);
! 		appendCSVLiteral(&buf, msgbuf.data);
  
! 		pfree(msgbuf.data);
! 	}
! 	appendStringInfoChar(&buf, ',');
  
! 	/* session start timestamp */
! 	if (formatted_start_time[0] == '\0')
! 		setup_formatted_start_time();
! 	appendStringInfoString(&buf, formatted_start_time);
! 	appendStringInfoChar(&buf, ',');
  
! 	/* Virtual transaction id */
! 	/* keep VXID format in sync with lockfuncs.c */
! 	if (MyProc != NULL && MyProc->backendId != InvalidBackendId)
! 		appendStringInfo(&buf, "%d/%u", MyProc->backendId, MyProc->lxid);
! 	appendStringInfoChar(&buf, ',');
  
! 	/* Transaction id */
! 	appendStringInfo(&buf, "%u", GetTopTransactionIdIfAny());
! 	appendStringInfoChar(&buf, ',');
  
! 	/* Error severity */
! 	appendStringInfoString(&buf, error_severity(edata->elevel));
! 	appendStringInfoChar(&buf, ',');
  
! 	/* SQL state code */
! 	appendStringInfoString(&buf, unpack_sql_state(edata->sqlerrcode));
! 	appendStringInfoChar(&buf, ',');
  
! 	/* errmessage */
! 	appendCSVLiteral(&buf, edata->message);
! 	appendStringInfoChar(&buf, ',');
  
! 	/* errdetail or errdetail_log */
! 	if (edata->detail_log)
! 		appendCSVLiteral(&buf, edata->detail_log);
! 	else
! 		appendCSVLiteral(&buf, edata->detail);
! 	appendStringInfoChar(&buf, ',');
  
! 	/* errhint */
! 	appendCSVLiteral(&buf, edata->hint);
! 	appendStringInfoChar(&buf, ',');
  
! 	/* internal query */
! 	appendCSVLiteral(&buf, edata->internalquery);
! 	appendStringInfoChar(&buf, ',');
  
! 	/* if printed internal query, print internal pos too */
! 	if (edata->internalpos > 0 && edata->internalquery != NULL)
! 		appendStringInfo(&buf, "%d", edata->internalpos);
! 	appendStringInfoChar(&buf, ',');
  
! 	/* errcontext */
! 	appendCSVLiteral(&buf, edata->context);
! 	appendStringInfoChar(&buf, ',');
  
! 	/* user query --- only reported if not disabled by the caller */
! 	if (is_log_level_output(edata->elevel, log_min_error_statement) &&
! 		debug_query_string != NULL &&
! 		!edata->hide_stmt)
! 		print_stmt = true;
! 	if (print_stmt)
! 		appendCSVLiteral(&buf, debug_query_string);
! 	appendStringInfoChar(&buf, ',');
! 	if (print_stmt && edata->cursorpos > 0)
! 		appendStringInfo(&buf, "%d", edata->cursorpos);
! 	appendStringInfoChar(&buf, ',');
! 
! 	/* file error location */
! 	if (Log_error_verbosity >= PGERROR_VERBOSE)
! 	{
! 		StringInfoData msgbuf;
! 
! 		initStringInfo(&msgbuf);
! 
! 		if (edata->funcname && edata->filename)
! 			appendStringInfo(&msgbuf, "%s, %s:%d",
! 							 edata->funcname, edata->filename,
! 							 edata->lineno);
! 		else if (edata->filename)
! 			appendStringInfo(&msgbuf, "%s:%d",
! 							 edata->filename, edata->lineno);
! 		appendCSVLiteral(&buf, msgbuf.data);
! 		pfree(msgbuf.data);
! 	}
! 	appendStringInfoChar(&buf, ',');
  
! 	/* application name */
! 	if (application_name)
! 		appendCSVLiteral(&buf, application_name);
  
  	appendStringInfoChar(&buf, '\n');
  
--- 2133,2381 ----
  	initStringInfo(&buf);
  
  	/*
! 	 * Get the number of fields, so we make sure to *not* include a comma
! 	 * after the last field.
  	 */
! 	num_fields = list_length(csvlog_field_list);
  
! 	/*
! 	 * Loop through the fields requested by the user, in the order requested, in
! 	 * the csvlog_fields GUC.
! 	 */
! 	foreach(l, csvlog_field_list)
! 	{
! 		/* If this isn't the first field, prepend a comma to seperate this
! 		 * field from the previous one */
! 		if (!first_field)
! 			appendStringInfoChar(&buf, ',');
! 		else
! 			first_field = false;
  
! 		switch (lfirst_int(l))
! 		{
! 			case CSVLOG_LOG_TIME:
! 				{
! 					/*
! 					 * timestamp with milliseconds
! 					 *
! 					 * Check if the timestamp is already calculated for the syslog message,
! 					 * and use it if so.  Otherwise, get the current timestamp.  This is done
! 					 * to put same timestamp in both syslog and csvlog messages.
! 					 */
! 					if (formatted_log_time[0] == '\0')
! 						setup_formatted_log_time();
! 
! 					appendStringInfoString(&buf, formatted_log_time);
! 				}
! 				break;
  
! 			case CSVLOG_USER_NAME:
! 				{
! 					/* session username, as done for %u */
! 					if (*session_auth != '\0')
! 						appendCSVLiteral(&buf, session_auth);
! 					else
! 						/* username */
! 						if (MyProcPort)
! 						{
! 							const char *username = MyProcPort->user_name;
! 							if (username == NULL || *username == '\0')
! 								username = _("[unknown]");
! 							appendCSVLiteral(&buf, MyProcPort->user_name);
! 						}
! 				}
! 				break;
  
! 			case CSVLOG_ROLE_NAME:
! 				/* current role, not updated if someone renames it in another
! 				 * session, of course */
! 				appendCSVLiteral(&buf, show_role());
! 				break;
  
! 			case CSVLOG_DATABASE_NAME:
! 				{
! 					/* database name */
! 					if (MyProcPort)
! 						appendCSVLiteral(&buf, MyProcPort->database_name);
! 				}
! 				break;
  
! 			case CSVLOG_PROCESS_ID:
! 				{
! 					/* Process id  */
! 					if (MyProcPid != 0)
! 						appendStringInfo(&buf, "%d", MyProcPid);
! 				}
! 				break;
  
! 			case CSVLOG_CONNECTION_FROM:
! 				{
! 					/* Remote host and port */
! 					if (MyProcPort && MyProcPort->remote_host)
! 					{
! 						appendStringInfoChar(&buf, '"');
! 						appendStringInfoString(&buf, MyProcPort->remote_host);
! 						if (MyProcPort->remote_port && MyProcPort->remote_port[0] != '\0')
! 						{
! 							appendStringInfoChar(&buf, ':');
! 							appendStringInfoString(&buf, MyProcPort->remote_port);
! 						}
! 						appendStringInfoChar(&buf, '"');
! 					}
! 				}
! 				break;
  
! 			case CSVLOG_SESSION_ID:
! 				/* session id */
! 				appendStringInfo(&buf, "%lx.%x", (long) MyStartTime, MyProcPid);
! 				break;
  
! 			case CSVLOG_SESSION_LINE_NUM:
! 				/* Line number */
! 				appendStringInfo(&buf, "%ld", log_line_number);
! 				break;
  
! 			case CSVLOG_COMMAND_TAG:
! 				{
! 					/* PS display */
! 					if (MyProcPort)
! 					{
! 						StringInfoData msgbuf;
! 						const char *psdisp;
! 						int			displen;
  
! 						initStringInfo(&msgbuf);
  
! 						psdisp = get_ps_display(&displen);
! 						appendBinaryStringInfo(&msgbuf, psdisp, displen);
! 						appendCSVLiteral(&buf, msgbuf.data);
  
! 						pfree(msgbuf.data);
! 					}
! 				}
! 				break;
  
! 			case CSVLOG_SESSION_START_TIME:
! 				{
! 					/* session start timestamp */
! 					if (formatted_start_time[0] == '\0')
! 						setup_formatted_start_time();
! 					appendStringInfoString(&buf, formatted_start_time);
! 				}
! 				break;
  
! 			case CSVLOG_VIRTUAL_TRANSACTION_ID:
! 				{
! 					/* Virtual transaction id */
! 					/* keep VXID format in sync with lockfuncs.c */
! 					if (MyProc != NULL && MyProc->backendId != InvalidBackendId)
! 						appendStringInfo(&buf, "%d/%u", MyProc->backendId, MyProc->lxid);
! 				}
! 				break;
  
! 			case CSVLOG_TRANSACTION_ID:
! 				/* Transaction id */
! 				appendStringInfo(&buf, "%u", GetTopTransactionIdIfAny());
! 				break;
  
! 			case CSVLOG_ERROR_SEVERITY:
! 				/* Error severity */
! 				appendStringInfoString(&buf, error_severity(edata->elevel));
! 				break;
  
! 			case CSVLOG_SQL_STATE_CODE:
! 				/* SQL state code */
! 				appendStringInfoString(&buf, unpack_sql_state(edata->sqlerrcode));
! 				break;
  
! 			case CSVLOG_MESSAGE:
! 				/* errmessage */
! 				appendCSVLiteral(&buf, edata->message);
! 				break;
  
! 			case CSVLOG_DETAIL:
! 				{
! 					/* errdetail or errdetail_log */
! 					if (edata->detail_log)
! 						appendCSVLiteral(&buf, edata->detail_log);
! 					else
! 						appendCSVLiteral(&buf, edata->detail);
! 				}
! 				break;
  
! 			case CSVLOG_HINT:
! 				/* errhint */
! 				appendCSVLiteral(&buf, edata->hint);
! 				break;
  
! 			case CSVLOG_INTERNAL_QUERY:
! 				/* internal query */
! 				appendCSVLiteral(&buf, edata->internalquery);
! 				break;
  
! 			case CSVLOG_INTERNAL_QUERY_POS:
! 				{
! 					/* if printed internal query, print internal pos too */
! 					if (edata->internalpos > 0 && edata->internalquery != NULL)
! 						appendStringInfo(&buf, "%d", edata->internalpos);
! 				}
! 				break;
  
! 			case CSVLOG_CONTEXT:
! 				/* errcontext */
! 				appendCSVLiteral(&buf, edata->context);
! 				break;
! 
! 			case CSVLOG_QUERY:
! 				{
! 					/* user query --- only reported if not disabled by the caller */
! 					if (is_log_level_output(edata->elevel, log_min_error_statement) &&
! 						debug_query_string != NULL &&
! 						!edata->hide_stmt)
! 						print_stmt = true;
! 					if (print_stmt)
! 						appendCSVLiteral(&buf, debug_query_string);
! 				}
! 				break;
! 
! 			case CSVLOG_QUERY_POS:
! 				{
! 					if (print_stmt && edata->cursorpos > 0)
! 						appendStringInfo(&buf, "%d", edata->cursorpos);
! 				}
! 				break;
! 
! 			case CSVLOG_LOCATION:
! 				{
! 					/* file error location */
! 					if (Log_error_verbosity >= PGERROR_VERBOSE)
! 					{
! 						StringInfoData msgbuf;
! 
! 						initStringInfo(&msgbuf);
! 
! 						if (edata->funcname && edata->filename)
! 							appendStringInfo(&msgbuf, "%s, %s:%d",
! 											 edata->funcname, edata->filename,
! 											 edata->lineno);
! 						else if (edata->filename)
! 							appendStringInfo(&msgbuf, "%s:%d",
! 											 edata->filename, edata->lineno);
! 						appendCSVLiteral(&buf, msgbuf.data);
! 						pfree(msgbuf.data);
! 					}
! 				}
! 				break;
! 
! 			case CSVLOG_APPLICATION_NAME:
! 				{
! 					/* application name */
! 					if (application_name)
! 						appendCSVLiteral(&buf, application_name);
! 				}
! 				break;
! 		}
! 	}
  
  	appendStringInfoChar(&buf, '\n');
  
*** a/src/backend/utils/misc/guc.c
--- b/src/backend/utils/misc/guc.c
***************
*** 65,70 ****
--- 65,71 ----
  #include "tsearch/ts_cache.h"
  #include "utils/builtins.h"
  #include "utils/bytea.h"
+ #include "utils/elog.h"
  #include "utils/guc_tables.h"
  #include "utils/memutils.h"
  #include "utils/pg_locale.h"
***************
*** 191,196 **** static char *config_enum_get_options(struct config_enum * record,
--- 192,200 ----
  						const char *prefix, const char *suffix,
  						const char *separator);
  
+ /* Needs to be defined here because elog.h can't #include guc.h */
+ extern const char *assign_csvlog_fields(const char *newval,
+                 bool doit, GucSource source);
  
  /*
   * Options for enum values defined in this module.
***************
*** 1034,1039 **** static struct config_bool ConfigureNamesBool[] =
--- 1038,1052 ----
  		false, NULL, NULL
  	},
  	{
+ 		{"csvlog_header", PGC_POSTMASTER, LOGGING_WHAT,
+ 			gettext_noop("Enables including a header on CSV log files."),
+ 			NULL,
+ 		},
+ 		&csvlog_header,
+ 		false, NULL, NULL
+ 	},
+ 
+ 	{
  		{"sql_inheritance", PGC_USERSET, COMPAT_OPTIONS_PREVIOUS,
  			gettext_noop("Causes subtables to be included by default in various commands."),
  			NULL
***************
*** 2326,2331 **** static struct config_string ConfigureNamesString[] =
--- 2339,2355 ----
  	},
  
  	{
+ 		{"csvlog_fields", PGC_POSTMASTER, LOGGING_WHAT,
+ 			gettext_noop("Controls fields logged to CSV logfiles."),
+ 			gettext_noop("If blank, the default set of fields is used."),
+ 			GUC_LIST_INPUT
+ 		},
+ 		&csvlog_fields,
+ 		"log_time, user_name, database_name, process_id, connection_from, session_id, session_line_num, command_tag, session_start_time, virtual_transaction_id, transaction_id, error_severity, sql_state_code, message, detail, hint, internal_query, internal_query_pos, context, query, query_pos, location, application_name",
+ 		assign_csvlog_fields, NULL
+ 	},
+ 
+ 	{
  		{"log_timezone", PGC_SIGHUP, LOGGING_WHAT,
  			gettext_noop("Sets the time zone to use in log messages."),
  			NULL
*** a/src/backend/utils/misc/postgresql.conf.sample
--- b/src/backend/utils/misc/postgresql.conf.sample
***************
*** 360,366 ****
  #log_hostname = off
  #log_line_prefix = ''			# special values:
  					#   %a = application name
! 					#   %u = user name
  					#   %d = database name
  					#   %r = remote host and port
  					#   %h = remote host
--- 360,367 ----
  #log_hostname = off
  #log_line_prefix = ''			# special values:
  					#   %a = application name
! 					#   %u = session user name
! 					#   %U = current role name
  					#   %d = database name
  					#   %r = remote host and port
  					#   %h = remote host
***************
*** 378,383 ****
--- 379,389 ----
  					#        processes
  					#   %% = '%'
  					# e.g. '<%u%%%d> '
+ 
+ # fields to include in the CSV log output
+ #csvlog_fields = 'log_time, user_name, database_name, process_id, connection_from, session_id, session_line_num, command_tag, session_start_time, virtual_transaction_id, transaction_id, error_severity, sql_state_code, message, detail, hint, internal_query, internal_query_pos, context, query, query_pos, location, application_name'
+ #csvlog_header = false			# should csvlog files have a header?
+ 
  #log_lock_waits = off			# log lock waits >= deadlock_timeout
  #log_statement = 'none'			# none, ddl, mod, all
  #log_temp_files = -1			# log temporary files equal or larger
*** a/src/include/utils/elog.h
--- b/src/include/utils/elog.h
***************
*** 330,337 **** typedef enum
--- 330,386 ----
  
  extern int	Log_error_verbosity;
  extern char *Log_line_prefix;
+ extern char *csvlog_fields; /* List of fields to log with CSV logging */
+ extern bool	csvlog_header; /* Whether to include a header on CSV log files */
  extern int	Log_destination;
  
+ /*
+  * Enum of the CSV fields we understand for CSV-based logging,
+  * if an new field is added, the enum has to be updated, the
+  * definition of field names in elog.c needs to be updated, and the
+  * new field needs to be handled in write_csv() in elog.c.
+  * Also be sure to update MAX_CSVLOG_OPTS if you change what the last
+  * option in the enum list is.
+  */
+ typedef enum LogCSVFields
+ {
+ 	CSVLOG_LOG_TIME,
+ 	CSVLOG_USER_NAME,
+ 	CSVLOG_ROLE_NAME,
+ 	CSVLOG_DATABASE_NAME,
+ 	CSVLOG_PROCESS_ID,
+ 	CSVLOG_CONNECTION_FROM,
+ 	CSVLOG_SESSION_ID,
+ 	CSVLOG_SESSION_LINE_NUM,
+ 	CSVLOG_COMMAND_TAG,
+ 	CSVLOG_SESSION_START_TIME,
+ 	CSVLOG_VIRTUAL_TRANSACTION_ID,
+ 	CSVLOG_TRANSACTION_ID,
+ 	CSVLOG_ERROR_SEVERITY,
+ 	CSVLOG_SQL_STATE_CODE,
+ 	CSVLOG_MESSAGE,
+ 	CSVLOG_DETAIL,
+ 	CSVLOG_HINT,
+ 	CSVLOG_INTERNAL_QUERY,
+ 	CSVLOG_INTERNAL_QUERY_POS,
+ 	CSVLOG_CONTEXT,
+ 	CSVLOG_QUERY,
+ 	CSVLOG_QUERY_POS,
+ 	CSVLOG_LOCATION,
+ 	CSVLOG_APPLICATION_NAME
+ } LogCSVFields;
+ 
+ /* Make sure to update this if you add CSV log options and change
+  * what the last CSVLOG option is */
+ #define MAX_CSVLOG_OPTS CSVLOG_APPLICATION_NAME+1
+ 
+ /*
+  * Array of the names of each of the CSV fields we allow for logging,
+  * if an new field is added, the enum has to be updated *and* the
+  * definition of field names in elog.c needs to be updated.
+  */
+ extern const char *CSVFieldNames[];
+ 
  /* Log destination bitmap */
  #define LOG_DESTINATION_STDERR	 1
  #define LOG_DESTINATION_SYSLOG	 2
*** a/src/tools/pgindent/typedefs.list
--- b/src/tools/pgindent/typedefs.list
***************
*** 855,860 **** LockTagType
--- 855,861 ----
  LockTupleMode
  LockingClause
  LogStmtLevel
+ LogCSVFields
  LogicalTape
  LogicalTapeSet
  MAGIC

*** a/doc/src/sgml/config.sgml
--- b/doc/src/sgml/config.sgml
***************
*** 3542,3548 **** local0.*    /var/log/postgresql
              </row>
              <row>
               <entry><literal>%u</literal></entry>
!              <entry>User name</entry>
               <entry>yes</entry>
              </row>
              <row>
--- 3542,3561 ----
              </row>
              <row>
               <entry><literal>%u</literal></entry>
!              <entry>Session user name, typically the user name which was used
!              to authenticate to <productname>PostgreSQL</productname> with,
!              but can be changed by a superuser, see <command>SET SESSION
!              AUTHORIZATION</></entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>%U</literal></entry>
!              <entry>Current role name, when set with <command>SET ROLE</>;
!              the current role identifier is relevant for permission checking;
!              Returns 'none' if the current role matches the session user.
!              Note: Log messages from inside <literal>SECURITY DEFINER</>
!              functions will show the calling role, not the effective role
!              inside the <literal>SECURITY DEFINER</> function</entry>
               <entry>yes</entry>
              </row>
              <row>
***************
*** 3659,3664 **** FROM pg_stat_activity;
--- 3672,3717 ----
        </listitem>
       </varlistentry>
  
+      <varlistentry id="guc-csvlog-fields" xreflabel="csvlog_fields">
+       <term><varname>csvlog_fields</varname> (<type>string</type>)</term>
+       <indexterm>
+        <primary><varname>csvlog_fields</> configuration parameter</primary>
+       </indexterm>
+       <listitem>
+        <para>
+         Controls the set and order of the fields which are written out in
+         the CSV-format log file.
+ 
+         The default is:
+         <literal>log_time, user_name, database_name, process_id,
+         connection_from, session_id, session_line_num, command_tag,
+         session_start_time, virtual_transaction_id, transaction_id,
+         error_severity, sql_state_code, message, detail, hint,
+         internal_query, internal_query_pos, context, query, query_pos,
+         location, application_name</literal>
+ 
+         For details on what these fields are, refer to the
+         <varname>log_line_prefix</varname> and
+         <xref linkend="runtime-config-logging-csvlog"> documentation.
+        </para>
+       </listitem>
+      </varlistentry>
+ 
+      <varlistentry id="guc-csvlog-header" xreflabel="csvlog_header">
+       <term><varname>csvlog_header</varname> (<type>boolean</type>)</term>
+       <indexterm>
+        <primary><varname>csvlog_header</> configuration parameter</primary>
+       </indexterm>
+       <listitem>
+        <para>
+         Controls if a header should be output for each file logged through
+         the CSV-format logging.
+ 
+         The default is: <literal>false</literal>, for backwards compatibility.
+        </para>
+       </listitem>
+      </varlistentry>
+ 
       <varlistentry id="guc-log-lock-waits" xreflabel="log_lock_waits">
        <term><varname>log_lock_waits</varname> (<type>boolean</type>)</term>
        <indexterm>
***************
*** 3766,3799 **** FROM pg_stat_activity;
          Including <literal>csvlog</> in the <varname>log_destination</> list
          provides a convenient way to import log files into a database table.
          This option emits log lines in comma-separated-values
!         (<acronym>CSV</>) format,
!         with these columns:
!         timestamp with milliseconds,
!         user name,
!         database name,
!         process ID,
!         client host:port number,
!         session ID,
!         per-session line number,
!         command tag,
!         session start time,
!         virtual transaction ID,
!         regular transaction ID,
!         error severity,
!         SQLSTATE code,
!         error message,
!         error message detail,
!         hint,
!         internal query that led to the error (if any),
!         character count of the error position therein,
!         error context,
!         user query that led to the error (if any and enabled by
!         <varname>log_min_error_statement</>),
!         character count of the error position therein,
!         location of the error in the PostgreSQL source code
!         (if <varname>log_error_verbosity</> is set to <literal>verbose</>),
!         and application name.
!         Here is a sample table definition for storing CSV-format log output:
  
  <programlisting>
  CREATE TABLE postgres_log
--- 3819,3971 ----
          Including <literal>csvlog</> in the <varname>log_destination</> list
          provides a convenient way to import log files into a database table.
          This option emits log lines in comma-separated-values
!         (<acronym>CSV</>) format.  The following table defines the fields
!         which can be included in the CSV output, their meanings, and if they
!         are included in the default CSV layout (the default ordering matches
!         the order of this table).
! 
!          <informaltable>
!           <tgroup cols="3">
!            <thead>
!             <row>
!              <entry>CSV Field Name</entry>
!              <entry>Definition</entry>
!              <entry>Included by Default</entry>
!              </row>
!             </thead>
!            <tbody>
!             <row>
!              <entry><literal>log_time</literal></entry>
!              <entry>timestamp with milliseconds</entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>user_name</literal></entry>
!              <entry>session user name</entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>role_name</literal></entry>
!              <entry>current role name</entry>
!              <entry>no</entry>
!             </row>
!             <row>
!              <entry><literal>database_name</literal></entry>
!              <entry>name of database connected to</entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>process_id</literal></entry>
!              <entry>process ID of the backend PG process</entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>connection_from</literal></entry>
!              <entry>client host/IP and port number</entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>session_id</literal></entry>
!              <entry>ID of the session</entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>session_line_number</literal></entry>
!              <entry>per-session line number</entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>command_tag</literal></entry>
!              <entry>Command tag of the logged command</entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>session_start_time</literal></entry>
!              <entry>Start time of the current session</entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>virtual_transaction_id</literal></entry>
!              <entry>Virtual Transaction ID</entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>transaction_id</literal></entry>
!              <entry>Regular Transaction ID</entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>error_severity</literal></entry>
!              <entry>Error severity code of the log message</entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>sql_state_code</literal></entry>
!              <entry>SQLSTATE code of the command being logged</entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>message</literal></entry>
!              <entry>Error message</entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>detail</literal></entry>
!              <entry>Error message detail</entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>hint</literal></entry>
!              <entry>Error message hint</entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>internal_query</literal></entry>
!              <entry>internal query that led to the error (if any)</entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>internal_query_pos</literal></entry>
!              <entry>character count of the error position of the internal query</entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>context</literal></entry>
!              <entry>error context</entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>query</literal></entry>
!              <entry>user query that led to the error (if any and enabled by <varname>log_min_error_statement</varname>)</entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>query_pos</literal></entry>
!              <entry>character count of the error position of the user query</entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>location</literal></entry>
!              <entry>location of the error in the PostgreSQL source code (if <varname>log_error_verbosity</varname> is set to <literal>verbose</literal>)</entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>application_name</literal></entry>
!              <entry>Name of the connecting application, if provided by the application</entry>
!              <entry>yes</entry>
!             </row>
!            </tbody>
!           </tgroup>
!          </informaltable>
! 
!         The set of columns to be included, and their order, in the CSV
!         output can be controlled using the <varname>csvlog_fields</varname> option.
! 
!         For additional details on the definition of the above columns, refer
!         to the documentation for <varname>log_line_prefix</varname>.
! 
!         Here is a sample table definition for storing the default CSV-format
!         log output:
  
  <programlisting>
  CREATE TABLE postgres_log
*** a/src/backend/commands/variable.c
--- b/src/backend/commands/variable.c
***************
*** 847,852 **** assign_session_authorization(const char *value, bool doit, GucSource source)
--- 847,857 ----
  	return result;
  }
  
+ /*
+  * function to return the stored session username, needed because we
+  * can't do catalog lookups when possibly being called after an error,
+  * eg: from elog.c or part of GUC handling.
+  */
  const char *
  show_session_authorization(void)
  {
***************
*** 972,977 **** assign_role(const char *value, bool doit, GucSource source)
--- 977,987 ----
  	return result;
  }
  
+ /*
+  * function to return the stored role username, needed because we
+  * can't do catalog lookups when possibly being called after an error,
+  * eg: from elog.c or part of GUC handling.
+  */
  const char *
  show_role(void)
  {
*** a/src/backend/postmaster/syslogger.c
--- b/src/backend/postmaster/syslogger.c
***************
*** 147,152 **** static char *logfile_getname(pg_time_t timestamp, const char *suffix);
--- 147,153 ----
  static void set_next_rotation_time(void);
  static void sigHupHandler(SIGNAL_ARGS);
  static void sigUsr1Handler(SIGNAL_ARGS);
+ static void write_csvlog_header(FILE *out_fh);
  
  
  /*
***************
*** 988,993 **** pipeThread(void *arg)
--- 989,1019 ----
  #endif   /* WIN32 */
  
  /*
+  * Internal function for writing out the header of a CSV-style log file
+  * to the passed-in file handle.
+  */
+ static void
+ write_csvlog_header(FILE *out_fh)
+ {
+ 	int				rc;
+ 	int				header_length = strlen(csvlog_fields);
+ 
+ 	/* Write out the csvlog_fields GUC, which matches the CSV log format
+ 	 * header, at least, if we did everything right. */
+ 	rc = fwrite(csvlog_fields, 1, header_length, out_fh);
+ 
+ 	/* can't use ereport here because of possible recursion */
+ 	if (rc != header_length)
+ 		write_stderr("could not write to new log file: %s\n", strerror(errno));
+ 
+ 	rc = fputc('\n', out_fh);
+ 	if (rc != '\n')
+ 		write_stderr("could not write to new log file: %s\n", strerror(errno));
+ 
+ 	return;
+ }
+ 
+ /*
   * open the csv log file - we do this opportunistically, because
   * we don't know if CSV logging will be wanted.
   */
***************
*** 995,1004 **** static void
  open_csvlogfile(void)
  {
  	char	   *filename;
  
  	filename = logfile_getname(time(NULL), ".csv");
  
! 	csvlogFile = logfile_open(filename, "a", false);
  
  	pfree(filename);
  }
--- 1021,1037 ----
  open_csvlogfile(void)
  {
  	char	   *filename;
+ 	FILE	   *fh;
  
  	filename = logfile_getname(time(NULL), ".csv");
  
! 	fh = logfile_open(filename, "a", false);
! 
! 	/* Check if we are asked to write out a header for the CSV file. */
! 	if (csvlog_header)
! 		write_csvlog_header(fh);
! 
! 	csvlogFile = fh;
  
  	pfree(filename);
  }
***************
*** 1165,1170 **** logfile_rotate(bool time_based_rotation, int size_rotation_for)
--- 1198,1207 ----
  			return;
  		}
  
+ 		/* Check if we are asked to write out a header for the CSV file. */
+ 		if (csvlog_header)
+ 			write_csvlog_header(fh);
+ 
  		fclose(csvlogFile);
  		csvlogFile = fh;
  
*** a/src/backend/utils/error/elog.c
--- b/src/backend/utils/error/elog.c
***************
*** 3,8 ****
--- 3,17 ----
   * elog.c
   *	  error logging and reporting
   *
+  * A few comments about situations where error processing is called:
+  *
+  * We need to be cautious of both a performance hit when logging, since
+  * log messages can be generated at a huge rate if every command is being
+  * logged and we also need to watch out for what can happen when we are
+  * trying to log from an aborted transaction.  Specifically, attempting to
+  * do SysCache lookups and possibly use other usually available backend
+  * systems will fail badly when logging from an aborted transaction.
+  *
   * Some notes about recursion and errors during error processing:
   *
   * We need to be robust about recursive-error scenarios --- for example,
***************
*** 59,73 ****
--- 68,85 ----
  
  #include "access/transam.h"
  #include "access/xact.h"
+ #include "commands/variable.h"
  #include "libpq/libpq.h"
  #include "libpq/pqformat.h"
  #include "mb/pg_wchar.h"
  #include "miscadmin.h"
+ #include "nodes/pg_list.h"
  #include "postmaster/postmaster.h"
  #include "postmaster/syslogger.h"
  #include "storage/ipc.h"
  #include "storage/proc.h"
  #include "tcop/tcopprot.h"
+ #include "utils/builtins.h"
  #include "utils/guc.h"
  #include "utils/memutils.h"
  #include "utils/ps_status.h"
***************
*** 93,98 **** extern bool redirection_done;
--- 105,144 ----
  int			Log_error_verbosity = PGERROR_VERBOSE;
  char	   *Log_line_prefix = NULL;		/* format for extra log line info */
  int			Log_destination = LOG_DESTINATION_STDERR;
+ char	   *csvlog_fields = NULL;
+ bool		csvlog_header = false;
+ 
+ static List *csvlog_field_list = NIL;
+ 
+ /* To add a CSV field option, you need to update the enum in elog.h, check
+  * if the last value in the enum changed and if so update MAX_CSVLOG_OPTS,
+  * add code to handle the option in write_csv(), and add it here. */
+ const char *CSVFieldNames[] = {
+ 	"log_time",					/* CSVLOG_LOG_TIME */
+ 	"user_name",				/* CSVLOG_USER_NAME */
+ 	"role_name",				/* CSVLOG_ROLE_NAME */
+ 	"database_name",			/* CSVLOG_DATABASE_NAME */
+ 	"process_id",				/* CSVLOG_PROCESS_ID */
+ 	"connection_from",			/* CSVLOG_CONNECTION_FROM */
+ 	"session_id",				/* CSVLOG_SESSION_ID */
+ 	"session_line_num",			/* CSVLOG_SESSION_LINE_NUM */
+ 	"command_tag",				/* CSVLOG_COMMAND_TAG */
+ 	"session_start_time",		/* CSVLOG_SESSION_START_TIME */
+ 	"virtual_transaction_id",	/* CSVLOG_VIRTUAL_TRANSACTION_ID */
+ 	"transaction_id",			/* CSVLOG_TRANSACTION_ID */
+ 	"error_severity",			/* CSVLOG_ERROR_SEVERITY */
+ 	"sql_state_code",			/* CSVLOG_SQL_STATE_CODE */
+ 	"message",					/* CSVLOG_MESSAGE */
+ 	"detail",					/* CSVLOG_DETAIL */
+ 	"hint",						/* CSVLOG_HINT */
+ 	"internal_query",			/* CSVLOG_INTERNAL_QUERY */
+ 	"internal_query_pos",		/* CSVLOG_INTERNAL_QUERY_POS */
+ 	"context",					/* CSVLOG_CONTEXT */
+ 	"query",					/* CSVLOG_QUERY */
+ 	"query_pos",				/* CSVLOG_QUERY_POS */
+ 	"location",					/* CSVLOG_LOCATION */
+ 	"application_name"			/* CSVLOG_APPLICATION_NAME */
+ };
  
  #ifdef HAVE_SYSLOG
  
***************
*** 161,166 **** static void write_csvlog(ErrorData *edata);
--- 207,217 ----
  static void setup_formatted_log_time(void);
  static void setup_formatted_start_time(void);
  
+ /* extern'd and used from guc.c... */
+ const char *assign_csvlog_fields(const char *newval, bool doit,
+ 								 GucSource source);
+ 
+ 
  
  /*
   * in_error_recursion_trouble --- are we at risk of infinite error recursion?
***************
*** 1817,1831 **** log_line_prefix(StringInfo buf, ErrorData *edata)
  				}
  				break;
  			case 'u':
- 				if (MyProcPort)
  				{
! 					const char *username = MyProcPort->user_name;
! 
! 					if (username == NULL || *username == '\0')
! 						username = _("[unknown]");
! 					appendStringInfoString(buf, username);
  				}
  				break;
  			case 'd':
  				if (MyProcPort)
  				{
--- 1868,1891 ----
  				}
  				break;
  			case 'u':
  				{
! 					const char *session_auth = show_session_authorization();
! 
! 					if (*session_auth != '\0')
! 						appendStringInfoString(buf, session_auth);
! 					else if (MyProcPort)
! 					{
! 						const char *username = MyProcPort->user_name;
! 
! 						if (username == NULL || *username == '\0')
! 							username = _("[unknown]");
! 						appendStringInfoString(buf, username);
! 					}
  				}
  				break;
+ 			case 'U':
+ 				appendStringInfoString(buf, show_role());
+ 				break;
  			case 'd':
  				if (MyProcPort)
  				{
***************
*** 1921,1926 **** log_line_prefix(StringInfo buf, ErrorData *edata)
--- 1981,2077 ----
  }
  
  /*
+  * Called when the GUC csvlog_fields() option has been set
+  * (currently only allowed in postmaster.conf, on PG restart).
+  *
+  * Processes the list passed in from the GUC system and updates the
+  * csvlog_field_list variable, which will then be used to generate
+  * CSV log output.
+  */
+ const char *
+ assign_csvlog_fields(const char *newval, bool doit, GucSource source)
+ {
+ 	/* Verify the list is valid */
+ 	List		*new_csv_fields = NIL;		/* List we're building */
+ 	List		*column_list = NIL;			/* List of columns from user */
+ 	ListCell	*l;
+ 	char		*rawstring;					/* Copy of user string */
+ 	MemoryContext oldcontext;
+ 
+ 	/* Need a modifyable version to pass to SplitIdentifierString */
+ 	rawstring = pstrdup(newval);
+ 
+     /* Parse string into list of identifiers */
+     if (!SplitIdentifierString(rawstring, ',', &column_list))
+ 	{
+ 		list_free(column_list);
+ 		pfree(rawstring);
+ 		return NULL;
+ 	}
+ 
+ 	/* Empty isn't a valid option */
+ 	if (column_list == NIL)
+ 	{
+ 		pfree(rawstring);
+ 		return NULL;
+ 	}
+ 
+ 	/*
+ 	 * We need the allocations done for the csvlog_field_list to
+ 	 * be preserved, so allocate them in TopMemoryContext.
+ 	 */
+ 	oldcontext = MemoryContextSwitchTo(TopMemoryContext);
+ 
+ 	/*
+ 	 * Loop through all of the fields provided by the user and build
+ 	 * up our new_csv_fields list which will be processed by write_csvlog
+ 	 */
+ 	foreach(l, column_list)
+ 	{
+ 		int curr_option;
+ 
+ 		/* Loop through all of the valid field options to try and match the
+ 		 * current entry in the list to one of them. */
+ 		for (curr_option = 0; curr_option < MAX_CSVLOG_OPTS; curr_option++)
+ 			if (pg_strcasecmp(lfirst(l),CSVFieldNames[curr_option]) == 0)
+ 			{
+ 				new_csv_fields = lappend_int(new_csv_fields,curr_option);
+ 				break;
+ 			}
+ 
+ 		/* check if no option matched, and if so, return error */
+ 		if (curr_option == MAX_CSVLOG_OPTS)
+ 		{
+ 			/* Switch back to the calling context */
+ 			MemoryContextSwitchTo(oldcontext);
+ 
+ 			list_free(column_list);
+ 			pfree(rawstring);
+ 
+ 			return NULL;
+ 		}
+ 	}
+ 
+ 	if (doit)
+ 	{
+ 		/* put new list in place */
+ 		List *old_list = csvlog_field_list;
+ 
+ 		csvlog_field_list = new_csv_fields;
+ 
+ 		list_free(old_list);
+ 	}
+ 
+ 	list_free(column_list);
+ 	pfree(rawstring);
+ 
+ 	/* Switch back to the calling context */
+ 	MemoryContextSwitchTo(oldcontext);
+ 
+ 	return newval;
+ }
+ 
+ /*
   * append a CSV'd version of a string to a StringInfo
   * We use the PostgreSQL defaults for CSV, i.e. quote = escape = '"'
   * If it's NULL, append nothing.
***************
*** 1946,1957 **** appendCSVLiteral(StringInfo buf, const char *data)
  }
  
  /*
!  * Constructs the error message, depending on the Errordata it gets, in a CSV
!  * format which is described in doc/src/sgml/config.sgml.
   */
  static void
  write_csvlog(ErrorData *edata)
  {
  	StringInfoData buf;
  	bool		print_stmt = false;
  
--- 2097,2110 ----
  }
  
  /*
!  * Constructs the error message, depending on the Errordata it gets, in the CSV
!  * format requested by the user, based on the csvlog_fields GUC.
   */
  static void
  write_csvlog(ErrorData *edata)
  {
+ 	int			num_fields;
+ 	bool		first_field = true;
  	StringInfoData buf;
  	bool		print_stmt = false;
  
***************
*** 1961,1966 **** write_csvlog(ErrorData *edata)
--- 2114,2126 ----
  	/* has counter been reset in current process? */
  	static int	log_my_pid = 0;
  
+ 	ListCell	*l;
+ 
+ 	const char *session_auth = show_session_authorization();
+ 
+ 	/* csvlog_field_list should never be empty when we reach here */
+ 	Assert(csvlog_field_list != NIL);
+ 
  	/*
  	 * This is one of the few places where we'd rather not inherit a static
  	 * variable's value from the postmaster.  But since we will, reset it when
***************
*** 1977,2134 **** write_csvlog(ErrorData *edata)
  	initStringInfo(&buf);
  
  	/*
! 	 * timestamp with milliseconds
! 	 *
! 	 * Check if the timestamp is already calculated for the syslog message,
! 	 * and use it if so.  Otherwise, get the current timestamp.  This is done
! 	 * to put same timestamp in both syslog and csvlog messages.
  	 */
! 	if (formatted_log_time[0] == '\0')
! 		setup_formatted_log_time();
  
! 	appendStringInfoString(&buf, formatted_log_time);
! 	appendStringInfoChar(&buf, ',');
  
! 	/* username */
! 	if (MyProcPort)
! 		appendCSVLiteral(&buf, MyProcPort->user_name);
! 	appendStringInfoChar(&buf, ',');
  
! 	/* database name */
! 	if (MyProcPort)
! 		appendCSVLiteral(&buf, MyProcPort->database_name);
! 	appendStringInfoChar(&buf, ',');
  
! 	/* Process id  */
! 	if (MyProcPid != 0)
! 		appendStringInfo(&buf, "%d", MyProcPid);
! 	appendStringInfoChar(&buf, ',');
  
! 	/* Remote host and port */
! 	if (MyProcPort && MyProcPort->remote_host)
! 	{
! 		appendStringInfoChar(&buf, '"');
! 		appendStringInfoString(&buf, MyProcPort->remote_host);
! 		if (MyProcPort->remote_port && MyProcPort->remote_port[0] != '\0')
! 		{
! 			appendStringInfoChar(&buf, ':');
! 			appendStringInfoString(&buf, MyProcPort->remote_port);
! 		}
! 		appendStringInfoChar(&buf, '"');
! 	}
! 	appendStringInfoChar(&buf, ',');
  
! 	/* session id */
! 	appendStringInfo(&buf, "%lx.%x", (long) MyStartTime, MyProcPid);
! 	appendStringInfoChar(&buf, ',');
  
! 	/* Line number */
! 	appendStringInfo(&buf, "%ld", log_line_number);
! 	appendStringInfoChar(&buf, ',');
  
! 	/* PS display */
! 	if (MyProcPort)
! 	{
! 		StringInfoData msgbuf;
! 		const char *psdisp;
! 		int			displen;
  
! 		initStringInfo(&msgbuf);
  
! 		psdisp = get_ps_display(&displen);
! 		appendBinaryStringInfo(&msgbuf, psdisp, displen);
! 		appendCSVLiteral(&buf, msgbuf.data);
  
! 		pfree(msgbuf.data);
! 	}
! 	appendStringInfoChar(&buf, ',');
  
! 	/* session start timestamp */
! 	if (formatted_start_time[0] == '\0')
! 		setup_formatted_start_time();
! 	appendStringInfoString(&buf, formatted_start_time);
! 	appendStringInfoChar(&buf, ',');
  
! 	/* Virtual transaction id */
! 	/* keep VXID format in sync with lockfuncs.c */
! 	if (MyProc != NULL && MyProc->backendId != InvalidBackendId)
! 		appendStringInfo(&buf, "%d/%u", MyProc->backendId, MyProc->lxid);
! 	appendStringInfoChar(&buf, ',');
  
! 	/* Transaction id */
! 	appendStringInfo(&buf, "%u", GetTopTransactionIdIfAny());
! 	appendStringInfoChar(&buf, ',');
  
! 	/* Error severity */
! 	appendStringInfoString(&buf, error_severity(edata->elevel));
! 	appendStringInfoChar(&buf, ',');
  
! 	/* SQL state code */
! 	appendStringInfoString(&buf, unpack_sql_state(edata->sqlerrcode));
! 	appendStringInfoChar(&buf, ',');
  
! 	/* errmessage */
! 	appendCSVLiteral(&buf, edata->message);
! 	appendStringInfoChar(&buf, ',');
  
! 	/* errdetail or errdetail_log */
! 	if (edata->detail_log)
! 		appendCSVLiteral(&buf, edata->detail_log);
! 	else
! 		appendCSVLiteral(&buf, edata->detail);
! 	appendStringInfoChar(&buf, ',');
  
! 	/* errhint */
! 	appendCSVLiteral(&buf, edata->hint);
! 	appendStringInfoChar(&buf, ',');
  
! 	/* internal query */
! 	appendCSVLiteral(&buf, edata->internalquery);
! 	appendStringInfoChar(&buf, ',');
  
! 	/* if printed internal query, print internal pos too */
! 	if (edata->internalpos > 0 && edata->internalquery != NULL)
! 		appendStringInfo(&buf, "%d", edata->internalpos);
! 	appendStringInfoChar(&buf, ',');
  
! 	/* errcontext */
! 	appendCSVLiteral(&buf, edata->context);
! 	appendStringInfoChar(&buf, ',');
  
! 	/* user query --- only reported if not disabled by the caller */
! 	if (is_log_level_output(edata->elevel, log_min_error_statement) &&
! 		debug_query_string != NULL &&
! 		!edata->hide_stmt)
! 		print_stmt = true;
! 	if (print_stmt)
! 		appendCSVLiteral(&buf, debug_query_string);
! 	appendStringInfoChar(&buf, ',');
! 	if (print_stmt && edata->cursorpos > 0)
! 		appendStringInfo(&buf, "%d", edata->cursorpos);
! 	appendStringInfoChar(&buf, ',');
! 
! 	/* file error location */
! 	if (Log_error_verbosity >= PGERROR_VERBOSE)
! 	{
! 		StringInfoData msgbuf;
! 
! 		initStringInfo(&msgbuf);
! 
! 		if (edata->funcname && edata->filename)
! 			appendStringInfo(&msgbuf, "%s, %s:%d",
! 							 edata->funcname, edata->filename,
! 							 edata->lineno);
! 		else if (edata->filename)
! 			appendStringInfo(&msgbuf, "%s:%d",
! 							 edata->filename, edata->lineno);
! 		appendCSVLiteral(&buf, msgbuf.data);
! 		pfree(msgbuf.data);
! 	}
! 	appendStringInfoChar(&buf, ',');
  
! 	/* application name */
! 	if (application_name)
! 		appendCSVLiteral(&buf, application_name);
  
  	appendStringInfoChar(&buf, '\n');
  
--- 2137,2385 ----
  	initStringInfo(&buf);
  
  	/*
! 	 * Get the number of fields, so we make sure to *not* include a comma
! 	 * after the last field.
  	 */
! 	num_fields = list_length(csvlog_field_list);
  
! 	/*
! 	 * Loop through the fields requested by the user, in the order requested, in
! 	 * the csvlog_fields GUC.
! 	 */
! 	foreach(l, csvlog_field_list)
! 	{
! 		/* If this isn't the first field, prepend a comma to seperate this
! 		 * field from the previous one */
! 		if (!first_field)
! 			appendStringInfoChar(&buf, ',');
! 		else
! 			first_field = false;
  
! 		switch (lfirst_int(l))
! 		{
! 			case CSVLOG_LOG_TIME:
! 				{
! 					/*
! 					 * timestamp with milliseconds
! 					 *
! 					 * Check if the timestamp is already calculated for the syslog message,
! 					 * and use it if so.  Otherwise, get the current timestamp.  This is done
! 					 * to put same timestamp in both syslog and csvlog messages.
! 					 */
! 					if (formatted_log_time[0] == '\0')
! 						setup_formatted_log_time();
! 
! 					appendStringInfoString(&buf, formatted_log_time);
! 				}
! 				break;
  
! 			case CSVLOG_USER_NAME:
! 				{
! 					/* session username, as done for %u */
! 					if (*session_auth != '\0')
! 						appendCSVLiteral(&buf, session_auth);
! 					else
! 						/* username */
! 						if (MyProcPort)
! 						{
! 							const char *username = MyProcPort->user_name;
! 							if (username == NULL || *username == '\0')
! 								username = _("[unknown]");
! 							appendCSVLiteral(&buf, MyProcPort->user_name);
! 						}
! 				}
! 				break;
  
! 			case CSVLOG_ROLE_NAME:
! 				/* current role, not updated if someone renames it in another
! 				 * session, of course */
! 				appendCSVLiteral(&buf, show_role());
! 				break;
  
! 			case CSVLOG_DATABASE_NAME:
! 				{
! 					/* database name */
! 					if (MyProcPort)
! 						appendCSVLiteral(&buf, MyProcPort->database_name);
! 				}
! 				break;
! 
! 			case CSVLOG_PROCESS_ID:
! 				{
! 					/* Process id  */
! 					if (MyProcPid != 0)
! 						appendStringInfo(&buf, "%d", MyProcPid);
! 				}
! 				break;
  
! 			case CSVLOG_CONNECTION_FROM:
! 				{
! 					/* Remote host and port */
! 					if (MyProcPort && MyProcPort->remote_host)
! 					{
! 						appendStringInfoChar(&buf, '"');
! 						appendStringInfoString(&buf, MyProcPort->remote_host);
! 						if (MyProcPort->remote_port && MyProcPort->remote_port[0] != '\0')
! 						{
! 							appendStringInfoChar(&buf, ':');
! 							appendStringInfoString(&buf, MyProcPort->remote_port);
! 						}
! 						appendStringInfoChar(&buf, '"');
! 					}
! 				}
! 				break;
  
! 			case CSVLOG_SESSION_ID:
! 				/* session id */
! 				appendStringInfo(&buf, "%lx.%x", (long) MyStartTime, MyProcPid);
! 				break;
  
! 			case CSVLOG_SESSION_LINE_NUM:
! 				/* Line number */
! 				appendStringInfo(&buf, "%ld", log_line_number);
! 				break;
  
! 			case CSVLOG_COMMAND_TAG:
! 				{
! 					/* PS display */
! 					if (MyProcPort)
! 					{
! 						StringInfoData msgbuf;
! 						const char *psdisp;
! 						int			displen;
  
! 						initStringInfo(&msgbuf);
  
! 						psdisp = get_ps_display(&displen);
! 						appendBinaryStringInfo(&msgbuf, psdisp, displen);
! 						appendCSVLiteral(&buf, msgbuf.data);
  
! 						pfree(msgbuf.data);
! 					}
! 				}
! 				break;
  
! 			case CSVLOG_SESSION_START_TIME:
! 				{
! 					/* session start timestamp */
! 					if (formatted_start_time[0] == '\0')
! 						setup_formatted_start_time();
! 					appendStringInfoString(&buf, formatted_start_time);
! 				}
! 				break;
  
! 			case CSVLOG_VIRTUAL_TRANSACTION_ID:
! 				{
! 					/* Virtual transaction id */
! 					/* keep VXID format in sync with lockfuncs.c */
! 					if (MyProc != NULL && MyProc->backendId != InvalidBackendId)
! 						appendStringInfo(&buf, "%d/%u", MyProc->backendId, MyProc->lxid);
! 				}
! 				break;
  
! 			case CSVLOG_TRANSACTION_ID:
! 				/* Transaction id */
! 				appendStringInfo(&buf, "%u", GetTopTransactionIdIfAny());
! 				break;
  
! 			case CSVLOG_ERROR_SEVERITY:
! 				/* Error severity */
! 				appendStringInfoString(&buf, error_severity(edata->elevel));
! 				break;
  
! 			case CSVLOG_SQL_STATE_CODE:
! 				/* SQL state code */
! 				appendStringInfoString(&buf, unpack_sql_state(edata->sqlerrcode));
! 				break;
  
! 			case CSVLOG_MESSAGE:
! 				/* errmessage */
! 				appendCSVLiteral(&buf, edata->message);
! 				break;
  
! 			case CSVLOG_DETAIL:
! 				{
! 					/* errdetail or errdetail_log */
! 					if (edata->detail_log)
! 						appendCSVLiteral(&buf, edata->detail_log);
! 					else
! 						appendCSVLiteral(&buf, edata->detail);
! 				}
! 				break;
! 
! 			case CSVLOG_HINT:
! 				/* errhint */
! 				appendCSVLiteral(&buf, edata->hint);
! 				break;
  
! 			case CSVLOG_INTERNAL_QUERY:
! 				/* internal query */
! 				appendCSVLiteral(&buf, edata->internalquery);
! 				break;
  
! 			case CSVLOG_INTERNAL_QUERY_POS:
! 				{
! 					/* if printed internal query, print internal pos too */
! 					if (edata->internalpos > 0 && edata->internalquery != NULL)
! 						appendStringInfo(&buf, "%d", edata->internalpos);
! 				}
! 				break;
  
! 			case CSVLOG_CONTEXT:
! 				/* errcontext */
! 				appendCSVLiteral(&buf, edata->context);
! 				break;
  
! 			case CSVLOG_QUERY:
! 				{
! 					/* user query --- only reported if not disabled by the caller */
! 					if (is_log_level_output(edata->elevel, log_min_error_statement) &&
! 						debug_query_string != NULL &&
! 						!edata->hide_stmt)
! 						print_stmt = true;
! 					if (print_stmt)
! 						appendCSVLiteral(&buf, debug_query_string);
! 				}
! 				break;
! 
! 			case CSVLOG_QUERY_POS:
! 				{
! 					if (print_stmt && edata->cursorpos > 0)
! 						appendStringInfo(&buf, "%d", edata->cursorpos);
! 				}
! 				break;
! 
! 			case CSVLOG_LOCATION:
! 				{
! 					/* file error location */
! 					if (Log_error_verbosity >= PGERROR_VERBOSE)
! 					{
! 						StringInfoData msgbuf;
! 
! 						initStringInfo(&msgbuf);
! 
! 						if (edata->funcname && edata->filename)
! 							appendStringInfo(&msgbuf, "%s, %s:%d",
! 											 edata->funcname, edata->filename,
! 											 edata->lineno);
! 						else if (edata->filename)
! 							appendStringInfo(&msgbuf, "%s:%d",
! 											 edata->filename, edata->lineno);
! 						appendCSVLiteral(&buf, msgbuf.data);
! 						pfree(msgbuf.data);
! 					}
! 				}
! 				break;
  
! 			case CSVLOG_APPLICATION_NAME:
! 				{
! 					/* application name */
! 					if (application_name)
! 						appendCSVLiteral(&buf, application_name);
! 				}
! 				break;
! 		}
! 	}
  
  	appendStringInfoChar(&buf, '\n');
  
*** a/src/backend/utils/misc/guc.c
--- b/src/backend/utils/misc/guc.c
***************
*** 65,70 ****
--- 65,71 ----
  #include "tsearch/ts_cache.h"
  #include "utils/builtins.h"
  #include "utils/bytea.h"
+ #include "utils/elog.h"
  #include "utils/guc_tables.h"
  #include "utils/memutils.h"
  #include "utils/pg_locale.h"
***************
*** 191,196 **** static char *config_enum_get_options(struct config_enum * record,
--- 192,200 ----
  						const char *prefix, const char *suffix,
  						const char *separator);
  
+ /* Needs to be defined here because elog.h can't #include guc.h */
+ extern const char *assign_csvlog_fields(const char *newval,
+                 bool doit, GucSource source);
  
  /*
   * Options for enum values defined in this module.
***************
*** 1034,1039 **** static struct config_bool ConfigureNamesBool[] =
--- 1038,1052 ----
  		false, NULL, NULL
  	},
  	{
+ 		{"csvlog_header", PGC_POSTMASTER, LOGGING_WHAT,
+ 			gettext_noop("Enables including a header on CSV log files."),
+ 			NULL,
+ 		},
+ 		&csvlog_header,
+ 		false, NULL, NULL
+ 	},
+ 
+ 	{
  		{"sql_inheritance", PGC_USERSET, COMPAT_OPTIONS_PREVIOUS,
  			gettext_noop("Causes subtables to be included by default in various commands."),
  			NULL
***************
*** 2326,2331 **** static struct config_string ConfigureNamesString[] =
--- 2339,2355 ----
  	},
  
  	{
+ 		{"csvlog_fields", PGC_POSTMASTER, LOGGING_WHAT,
+ 			gettext_noop("Controls fields logged to CSV logfiles."),
+ 			gettext_noop("If blank, the default set of fields is used."),
+ 			GUC_LIST_INPUT
+ 		},
+ 		&csvlog_fields,
+ 		"log_time, user_name, database_name, process_id, connection_from, session_id, session_line_num, command_tag, session_start_time, virtual_transaction_id, transaction_id, error_severity, sql_state_code, message, detail, hint, internal_query, internal_query_pos, context, query, query_pos, location, application_name",
+ 		assign_csvlog_fields, NULL
+ 	},
+ 
+ 	{
  		{"log_timezone", PGC_SIGHUP, LOGGING_WHAT,
  			gettext_noop("Sets the time zone to use in log messages."),
  			NULL
*** a/src/backend/utils/misc/postgresql.conf.sample
--- b/src/backend/utils/misc/postgresql.conf.sample
***************
*** 360,366 ****
  #log_hostname = off
  #log_line_prefix = ''			# special values:
  					#   %a = application name
! 					#   %u = user name
  					#   %d = database name
  					#   %r = remote host and port
  					#   %h = remote host
--- 360,367 ----
  #log_hostname = off
  #log_line_prefix = ''			# special values:
  					#   %a = application name
! 					#   %u = session user name
! 					#   %U = current role name
  					#   %d = database name
  					#   %r = remote host and port
  					#   %h = remote host
***************
*** 378,383 ****
--- 379,389 ----
  					#        processes
  					#   %% = '%'
  					# e.g. '<%u%%%d> '
+ 
+ # fields to include in the CSV log output
+ #csvlog_fields = 'log_time, user_name, database_name, process_id, connection_from, session_id, session_line_num, command_tag, session_start_time, virtual_transaction_id, transaction_id, error_severity, sql_state_code, message, detail, hint, internal_query, internal_query_pos, context, query, query_pos, location, application_name'
+ #csvlog_header = false			# should csvlog files have a header?
+ 
  #log_lock_waits = off			# log lock waits >= deadlock_timeout
  #log_statement = 'none'			# none, ddl, mod, all
  #log_temp_files = -1			# log temporary files equal or larger
*** a/src/include/utils/elog.h
--- b/src/include/utils/elog.h
***************
*** 330,337 **** typedef enum
--- 330,386 ----
  
  extern int	Log_error_verbosity;
  extern char *Log_line_prefix;
+ extern char *csvlog_fields; /* List of fields to log with CSV logging */
+ extern bool	csvlog_header; /* Whether to include a header on CSV log files */
  extern int	Log_destination;
  
+ /*
+  * Enum of the CSV fields we understand for CSV-based logging,
+  * if an new field is added, the enum has to be updated, the
+  * definition of field names in elog.c needs to be updated, and the
+  * new field needs to be handled in write_csv() in elog.c.
+  * Also be sure to update MAX_CSVLOG_OPTS if you change what the last
+  * option in the enum list is.
+  */
+ typedef enum LogCSVFields
+ {
+ 	CSVLOG_LOG_TIME,
+ 	CSVLOG_USER_NAME,
+ 	CSVLOG_ROLE_NAME,
+ 	CSVLOG_DATABASE_NAME,
+ 	CSVLOG_PROCESS_ID,
+ 	CSVLOG_CONNECTION_FROM,
+ 	CSVLOG_SESSION_ID,
+ 	CSVLOG_SESSION_LINE_NUM,
+ 	CSVLOG_COMMAND_TAG,
+ 	CSVLOG_SESSION_START_TIME,
+ 	CSVLOG_VIRTUAL_TRANSACTION_ID,
+ 	CSVLOG_TRANSACTION_ID,
+ 	CSVLOG_ERROR_SEVERITY,
+ 	CSVLOG_SQL_STATE_CODE,
+ 	CSVLOG_MESSAGE,
+ 	CSVLOG_DETAIL,
+ 	CSVLOG_HINT,
+ 	CSVLOG_INTERNAL_QUERY,
+ 	CSVLOG_INTERNAL_QUERY_POS,
+ 	CSVLOG_CONTEXT,
+ 	CSVLOG_QUERY,
+ 	CSVLOG_QUERY_POS,
+ 	CSVLOG_LOCATION,
+ 	CSVLOG_APPLICATION_NAME
+ } LogCSVFields;
+ 
+ /* Make sure to update this if you add CSV log options and change
+  * what the last CSVLOG option is */
+ #define MAX_CSVLOG_OPTS CSVLOG_APPLICATION_NAME+1
+ 
+ /*
+  * Array of the names of each of the CSV fields we allow for logging,
+  * if an new field is added, the enum has to be updated *and* the
+  * definition of field names in elog.c needs to be updated.
+  */
+ extern const char *CSVFieldNames[];
+ 
  /* Log destination bitmap */
  #define LOG_DESTINATION_STDERR	 1
  #define LOG_DESTINATION_SYSLOG	 2
*** a/src/tools/pgindent/typedefs.list
--- b/src/tools/pgindent/typedefs.list
***************
*** 855,860 **** LockTagType
--- 855,861 ----
  LockTupleMode
  LockingClause
  LogStmtLevel
+ LogCSVFields
  LogicalTape
  LogicalTapeSet
  MAGIC

*** a/doc/src/sgml/config.sgml
--- b/doc/src/sgml/config.sgml
***************
*** 3542,3548 **** local0.*    /var/log/postgresql
              </row>
              <row>
               <entry><literal>%u</literal></entry>
!              <entry>User name</entry>
               <entry>yes</entry>
              </row>
              <row>
--- 3542,3561 ----
              </row>
              <row>
               <entry><literal>%u</literal></entry>
!              <entry>Session user name, typically the user name which was used
!              to authenticate to <productname>PostgreSQL</productname> with,
!              but can be changed by a superuser, see <command>SET SESSION
!              AUTHORIZATION</></entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>%U</literal></entry>
!              <entry>Current role name, when set with <command>SET ROLE</>;
!              the current role identifier is relevant for permission checking;
!              Returns 'none' if the current role matches the session user.
!              Note: Log messages from inside <literal>SECURITY DEFINER</>
!              functions will show the calling role, not the effective role
!              inside the <literal>SECURITY DEFINER</> function</entry>
               <entry>yes</entry>
              </row>
              <row>
*** a/src/backend/commands/variable.c
--- b/src/backend/commands/variable.c
***************
*** 847,852 **** assign_session_authorization(const char *value, bool doit, GucSource source)
--- 847,857 ----
  	return result;
  }
  
+ /*
+  * function to return the stored session username, needed because we
+  * can't do catalog lookups when possibly being called after an error,
+  * eg: from elog.c or part of GUC handling.
+  */
  const char *
  show_session_authorization(void)
  {
***************
*** 972,977 **** assign_role(const char *value, bool doit, GucSource source)
--- 977,987 ----
  	return result;
  }
  
+ /*
+  * function to return the stored role username, needed because we
+  * can't do catalog lookups when possibly being called after an error,
+  * eg: from elog.c or part of GUC handling.
+  */
  const char *
  show_role(void)
  {
*** a/src/backend/utils/error/elog.c
--- b/src/backend/utils/error/elog.c
***************
*** 3,8 ****
--- 3,17 ----
   * elog.c
   *	  error logging and reporting
   *
+  * A few comments about situations where error processing is called:
+  *
+  * We need to be cautious of both a performance hit when logging, since
+  * log messages can be generated at a huge rate if every command is being
+  * logged and we also need to watch out for what can happen when we are
+  * trying to log from an aborted transaction.  Specifically, attempting to
+  * do SysCache lookups and possibly use other usually available backend
+  * systems will fail badly when logging from an aborted transaction.
+  *
   * Some notes about recursion and errors during error processing:
   *
   * We need to be robust about recursive-error scenarios --- for example,
***************
*** 1817,1831 **** log_line_prefix(StringInfo buf, ErrorData *edata)
  				}
  				break;
  			case 'u':
- 				if (MyProcPort)
  				{
! 					const char *username = MyProcPort->user_name;
! 
! 					if (username == NULL || *username == '\0')
! 						username = _("[unknown]");
! 					appendStringInfoString(buf, username);
  				}
  				break;
  			case 'd':
  				if (MyProcPort)
  				{
--- 1826,1849 ----
  				}
  				break;
  			case 'u':
  				{
! 					const char *session_auth = show_session_authorization();
! 
! 					if (*session_auth != '\0')
! 						appendStringInfoString(buf, session_auth);
! 					else if (MyProcPort)
! 					{
! 						const char *username = MyProcPort->user_name;
! 
! 						if (username == NULL || *username == '\0')
! 							username = _("[unknown]");
! 						appendStringInfoString(buf, username);
! 					}
  				}
  				break;
+ 			case 'U':
+ 				appendStringInfoString(buf, show_role());
+ 				break;
  			case 'd':
  				if (MyProcPort)
  				{
*** a/src/backend/utils/misc/postgresql.conf.sample
--- b/src/backend/utils/misc/postgresql.conf.sample
***************
*** 360,366 ****
  #log_hostname = off
  #log_line_prefix = ''			# special values:
  					#   %a = application name
! 					#   %u = user name
  					#   %d = database name
  					#   %r = remote host and port
  					#   %h = remote host
--- 360,367 ----
  #log_hostname = off
  #log_line_prefix = ''			# special values:
  					#   %a = application name
! 					#   %u = session user name
! 					#   %U = current role name
  					#   %d = database name
  					#   %r = remote host and port
  					#   %h = remote host

*** a/doc/src/sgml/config.sgml
--- b/doc/src/sgml/config.sgml
***************
*** 3562,3568 **** local0.*    /var/log/postgresql
              </row>
              <row>
               <entry><literal>%u</literal></entry>
!              <entry>User name</entry>
               <entry>yes</entry>
              </row>
              <row>
--- 3562,3581 ----
              </row>
              <row>
               <entry><literal>%u</literal></entry>
!              <entry>Session user name, typically the user name which was used
!              to authenticate to <productname>PostgreSQL</productname> with,
!              but can be changed by a superuser, see <command>SET SESSION
!              AUTHORIZATION</></entry>
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>%U</literal></entry>
!              <entry>Current role name, when set with <command>SET ROLE</>;
!              the current role identifier is relevant for permission checking;
!              Returns 'none' if the current role matches the session user.
!              Note: Log messages from inside <literal>SECURITY DEFINER</>
!              functions will show the calling role, not the effective role
!              inside the <literal>SECURITY DEFINER</> function</entry>
               <entry>yes</entry>
              </row>
              <row>
***************
*** 3790,3795 **** FROM pg_stat_activity;
--- 3803,3809 ----
          with these columns:
          timestamp with milliseconds,
          user name,
+         current role name,
          database name,
          process ID,
          client host:port number,
***************
*** 3820,3825 **** CREATE TABLE postgres_log
--- 3834,3840 ----
  (
    log_time timestamp(3) with time zone,
    user_name text,
+   curr_role text,
    database_name text,
    process_id integer,
    connection_from text,
*** a/src/backend/commands/variable.c
--- b/src/backend/commands/variable.c
***************
*** 847,852 **** assign_session_authorization(const char *value, bool doit, GucSource source)
--- 847,857 ----
  	return result;
  }
  
+ /*
+  * function to return the stored session username, needed because we
+  * can't do catalog lookups when possibly being called after an error,
+  * eg: from elog.c or part of GUC handling.
+  */
  const char *
  show_session_authorization(void)
  {
***************
*** 972,977 **** assign_role(const char *value, bool doit, GucSource source)
--- 977,987 ----
  	return result;
  }
  
+ /*
+  * function to return the stored role username, needed because we
+  * can't do catalog lookups when possibly being called after an error,
+  * eg: from elog.c or part of GUC handling.
+  */
  const char *
  show_role(void)
  {
*** a/src/backend/utils/error/elog.c
--- b/src/backend/utils/error/elog.c
***************
*** 3,8 ****
--- 3,17 ----
   * elog.c
   *	  error logging and reporting
   *
+  * A few comments about situations where error processing is called:
+  *
+  * We need to be cautious of both a performance hit when logging, since
+  * log messages can be generated at a huge rate if every command is being
+  * logged and we also need to watch out for what can happen when we are
+  * trying to log from an aborted transaction.  Specifically, attempting to
+  * do SysCache lookups and possibly use other usually available backend
+  * systems will fail badly when logging from an aborted transaction.
+  *
   * Some notes about recursion and errors during error processing:
   *
   * We need to be robust about recursive-error scenarios --- for example,
***************
*** 59,64 ****
--- 68,74 ----
  
  #include "access/transam.h"
  #include "access/xact.h"
+ #include "commands/variable.h"
  #include "libpq/libpq.h"
  #include "libpq/pqformat.h"
  #include "mb/pg_wchar.h"
***************
*** 1817,1831 **** log_line_prefix(StringInfo buf, ErrorData *edata)
  				}
  				break;
  			case 'u':
- 				if (MyProcPort)
  				{
! 					const char *username = MyProcPort->user_name;
! 
! 					if (username == NULL || *username == '\0')
! 						username = _("[unknown]");
! 					appendStringInfoString(buf, username);
  				}
  				break;
  			case 'd':
  				if (MyProcPort)
  				{
--- 1827,1854 ----
  				}
  				break;
  			case 'u':
  				{
! 					const char *session_auth = show_session_authorization();
! 
! 					/*
! 					 * If show_session_authorization() just returns an empty
! 					 * string, then use user_name from MyProcPort
! 					 */
! 					if (*session_auth != '\0')
! 						appendStringInfoString(buf, session_auth);
! 					else if (MyProcPort)
! 					{
! 						const char *username = MyProcPort->user_name;
! 
! 						if (username == NULL || *username == '\0')
! 							username = _("[unknown]");
! 						appendStringInfoString(buf, username);
! 					}
  				}
  				break;
+ 			case 'U':
+ 				appendStringInfoString(buf, show_role());
+ 				break;
  			case 'd':
  				if (MyProcPort)
  				{
***************
*** 1961,1966 **** write_csvlog(ErrorData *edata)
--- 1984,1992 ----
  	/* has counter been reset in current process? */
  	static int	log_my_pid = 0;
  
+ 	/* pull the session authorization */
+ 	const char *session_auth = show_session_authorization();
+ 
  	/*
  	 * This is one of the few places where we'd rather not inherit a static
  	 * variable's value from the postmaster.  But since we will, reset it when
***************
*** 1989,1999 **** write_csvlog(ErrorData *edata)
  	appendStringInfoString(&buf, formatted_log_time);
  	appendStringInfoChar(&buf, ',');
  
! 	/* username */
! 	if (MyProcPort)
  		appendCSVLiteral(&buf, MyProcPort->user_name);
  	appendStringInfoChar(&buf, ',');
  
  	/* database name */
  	if (MyProcPort)
  		appendCSVLiteral(&buf, MyProcPort->database_name);
--- 2015,2036 ----
  	appendStringInfoString(&buf, formatted_log_time);
  	appendStringInfoChar(&buf, ',');
  
! 	/*
! 	 * session username, as %u from log_line_prefix
! 	 *
! 	 * If show_session_authorization() returned an empty
! 	 * string, then use user_name from MyProcPort
! 	 */
! 	if (*session_auth != '\0')
! 		appendCSVLiteral(&buf, session_auth);
! 	else if (MyProcPort)
  		appendCSVLiteral(&buf, MyProcPort->user_name);
  	appendStringInfoChar(&buf, ',');
  
+ 	/* current role name, matches %U in log_line_prefix */
+ 	appendStringInfoString(&buf, show_role());
+ 	appendStringInfoChar(&buf, ',');
+ 
  	/* database name */
  	if (MyProcPort)
  		appendCSVLiteral(&buf, MyProcPort->database_name);
*** a/src/backend/utils/misc/postgresql.conf.sample
--- b/src/backend/utils/misc/postgresql.conf.sample
***************
*** 361,367 ****
  #log_hostname = off
  #log_line_prefix = ''			# special values:
  					#   %a = application name
! 					#   %u = user name
  					#   %d = database name
  					#   %r = remote host and port
  					#   %h = remote host
--- 361,368 ----
  #log_hostname = off
  #log_line_prefix = ''			# special values:
  					#   %a = application name
! 					#   %u = session user name
! 					#   %U = current role name
  					#   %d = database name
  					#   %r = remote host and port
  					#   %h = remote host

*** a/doc/src/sgml/config.sgml
--- b/doc/src/sgml/config.sgml
***************
*** 3562,3568 **** local0.*    /var/log/postgresql
              </row>
              <row>
               <entry><literal>%u</literal></entry>
!              <entry>User name</entry>
               <entry>yes</entry>
              </row>
              <row>
--- 3562,3579 ----
              </row>
              <row>
               <entry><literal>%u</literal></entry>
!              <entry>Authenticated user name, the user name that the user used
!              to authenticate to <productname>PostgreSQL</productname> with.
!              <entry>yes</entry>
!             </row>
!             <row>
!              <entry><literal>%U</literal></entry>
!              <entry>Current role being used for permissions checking, can be
!              set with <command>SET ROLE</> or <command>SET SESSION
!              AUTHORIZATION</> (only allowed for superusers);
!              Note: Log messages from inside <literal>SECURITY DEFINER</>
!              functions will show the calling role, not the effective role
!              inside the <literal>SECURITY DEFINER</> function</entry>
               <entry>yes</entry>
              </row>
              <row>
***************
*** 3790,3795 **** FROM pg_stat_activity;
--- 3801,3807 ----
          with these columns:
          timestamp with milliseconds,
          user name,
+         current role name,
          database name,
          process ID,
          client host:port number,
***************
*** 3820,3825 **** CREATE TABLE postgres_log
--- 3832,3838 ----
  (
    log_time timestamp(3) with time zone,
    user_name text,
+   curr_role text,
    database_name text,
    process_id integer,
    connection_from text,
*** a/src/backend/commands/variable.c
--- b/src/backend/commands/variable.c
***************
*** 847,852 **** assign_session_authorization(const char *value, bool doit, GucSource source)
--- 847,857 ----
  	return result;
  }
  
+ /*
+  * function to return the stored session username, needed because we
+  * can't do catalog lookups when possibly being called after an error,
+  * eg: from elog.c or part of GUC handling.
+  */
  const char *
  show_session_authorization(void)
  {
***************
*** 972,977 **** assign_role(const char *value, bool doit, GucSource source)
--- 977,987 ----
  	return result;
  }
  
+ /*
+  * function to return the stored role username, needed because we
+  * can't do catalog lookups when possibly being called after an error,
+  * eg: from elog.c or part of GUC handling.
+  */
  const char *
  show_role(void)
  {
*** a/src/backend/utils/error/elog.c
--- b/src/backend/utils/error/elog.c
***************
*** 65,70 ****
--- 65,71 ----
  
  #include "access/transam.h"
  #include "access/xact.h"
+ #include "commands/variable.h"
  #include "libpq/libpq.h"
  #include "libpq/pqformat.h"
  #include "mb/pg_wchar.h"
***************
*** 1777,1782 **** log_line_prefix(StringInfo buf, ErrorData *edata)
--- 1778,1795 ----
  	int			format_len;
  	int			i;
  
+ 	/* gather current session and role names */
+ 	const char *session_auth = show_session_authorization();
+ 	const char *role_auth = show_role();
+ 
+ 	/* what we'll actually log as current role, based on if
+ 	 * a set role has been done or not */
+ 	char	   *curr_role = role_auth;
+ 
+ 	/* if show_role() returns 'none', then we log the session user instead */
+ 	if (strcmp(role_auth,"none") == 0)
+ 		curr_role = session_auth;
+ 
  	/*
  	 * This is one of the few places where we'd rather not inherit a static
  	 * variable's value from the postmaster.  But since we will, reset it when
***************
*** 1832,1837 **** log_line_prefix(StringInfo buf, ErrorData *edata)
--- 1845,1853 ----
  					appendStringInfoString(buf, username);
  				}
  				break;
+ 			case 'U':
+ 				appendStringInfoString(buf, curr_role);
+ 				break;
  			case 'd':
  				if (MyProcPort)
  				{
***************
*** 1967,1972 **** write_csvlog(ErrorData *edata)
--- 1983,2000 ----
  	/* has counter been reset in current process? */
  	static int	log_my_pid = 0;
  
+ 	/* pull the session authorization */
+ 	const char *session_auth = show_session_authorization();
+ 	const char *role_auth = show_role();
+ 
+ 	/* what we'll actually log as current role, based on if
+ 	 * a set role has been done or not */
+ 	char	   *curr_role = role_auth;
+ 
+ 	/* if show_role() returns 'none', then we log the session user instead */
+ 	if (strcmp(role_auth,"none") == 0)
+ 		curr_role = session_auth;
+ 
  	/*
  	 * This is one of the few places where we'd rather not inherit a static
  	 * variable's value from the postmaster.  But since we will, reset it when
***************
*** 1995,2005 **** write_csvlog(ErrorData *edata)
  	appendStringInfoString(&buf, formatted_log_time);
  	appendStringInfoChar(&buf, ',');
  
! 	/* username */
  	if (MyProcPort)
  		appendCSVLiteral(&buf, MyProcPort->user_name);
  	appendStringInfoChar(&buf, ',');
  
  	/* database name */
  	if (MyProcPort)
  		appendCSVLiteral(&buf, MyProcPort->database_name);
--- 2023,2037 ----
  	appendStringInfoString(&buf, formatted_log_time);
  	appendStringInfoChar(&buf, ',');
  
! 	/* authenticated-with username */
  	if (MyProcPort)
  		appendCSVLiteral(&buf, MyProcPort->user_name);
  	appendStringInfoChar(&buf, ',');
  
+ 	/* current role name, matches %U in log_line_prefix */
+ 	appendStringInfoString(&buf, curr_role);
+ 	appendStringInfoChar(&buf, ',');
+ 
  	/* database name */
  	if (MyProcPort)
  		appendCSVLiteral(&buf, MyProcPort->database_name);
*** a/src/backend/utils/misc/postgresql.conf.sample
--- b/src/backend/utils/misc/postgresql.conf.sample
***************
*** 361,367 ****
  #log_hostname = off
  #log_line_prefix = ''			# special values:
  					#   %a = application name
! 					#   %u = user name
  					#   %d = database name
  					#   %r = remote host and port
  					#   %h = remote host
--- 361,368 ----
  #log_hostname = off
  #log_line_prefix = ''			# special values:
  					#   %a = application name
! 					#   %u = authenticated user name
! 					#   %U = current role name
  					#   %d = database name
  					#   %r = remote host and port
  					#   %h = remote host

diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml
index cee09c7..023e3f7 100644
--- a/doc/src/sgml/config.sgml
+++ b/doc/src/sgml/config.sgml
@@ -3562,7 +3562,14 @@ local0.*    /var/log/postgresql
             </row>
             <row>
              <entry><literal>%u</literal></entry>
-             <entry>User name</entry>
+             <entry>The user name used for authentication</entry>
+             <entry>yes</entry>
+            </row>
+            <row>
+             <entry><literal>%U</literal></entry>
+             <entry>The user name set via <xref linkend="sql-set-role">
+             or <xref linkend="sql-set-session-authorization">, if any,
+             or the authenticated username, otherwise</entry>
              <entry>yes</entry>
             </row>
             <row>
@@ -3790,6 +3797,7 @@ FROM pg_stat_activity;
         with these columns:
         timestamp with milliseconds,
         user name,
+        current role name,
         database name,
         process ID,
         client host:port number,
@@ -3820,6 +3828,7 @@ CREATE TABLE postgres_log
 (
   log_time timestamp(3) with time zone,
   user_name text,
+  curr_role text,
   database_name text,
   process_id integer,
   connection_from text,
diff --git a/src/backend/utils/error/elog.c b/src/backend/utils/error/elog.c
index 5679d5b..509755f 100644
--- a/src/backend/utils/error/elog.c
+++ b/src/backend/utils/error/elog.c
@@ -65,6 +65,7 @@
 
 #include "access/transam.h"
 #include "access/xact.h"
+#include "commands/variable.h"
 #include "libpq/libpq.h"
 #include "libpq/pqformat.h"
 #include "mb/pg_wchar.h"
@@ -1832,6 +1833,20 @@ log_line_prefix(StringInfo buf, ErrorData *edata)
 					appendStringInfoString(buf, username);
 				}
 				break;
+			case 'U':
+				{
+					const char *curr_role;
+
+					/*
+					 * You can't actually have a role named 'none', so this is
+					 * safer than it looks.
+					 */
+					curr_role = show_role();
+					if (strcmp(curr_role, "none") == 0)
+						curr_role = show_session_authorization();
+					appendStringInfoString(buf, curr_role);
+				}
+				break;
 			case 'd':
 				if (MyProcPort)
 				{
@@ -1967,6 +1982,16 @@ write_csvlog(ErrorData *edata)
 	/* has counter been reset in current process? */
 	static int	log_my_pid = 0;
 
+	const char  *curr_role;
+
+	/*
+	 * You can't actually have a role named 'none', so this is safer than
+	 * it looks.
+	 */
+	curr_role = show_role();
+	if (strcmp(curr_role, "none") == 0)
+		curr_role = show_session_authorization();
+
 	/*
 	 * This is one of the few places where we'd rather not inherit a static
 	 * variable's value from the postmaster.  But since we will, reset it when
@@ -1995,11 +2020,15 @@ write_csvlog(ErrorData *edata)
 	appendStringInfoString(&buf, formatted_log_time);
 	appendStringInfoChar(&buf, ',');
 
-	/* username */
+	/* authenticated-with username */
 	if (MyProcPort)
 		appendCSVLiteral(&buf, MyProcPort->user_name);
 	appendStringInfoChar(&buf, ',');
 
+	/* current role name, matches %U in log_line_prefix */
+	appendCSVLiteral(&buf, curr_role);
+	appendStringInfoChar(&buf, ',');
+
 	/* database name */
 	if (MyProcPort)
 		appendCSVLiteral(&buf, MyProcPort->database_name);
diff --git a/src/backend/utils/misc/postgresql.conf.sample b/src/backend/utils/misc/postgresql.conf.sample
index 6726733..0db585b 100644
--- a/src/backend/utils/misc/postgresql.conf.sample
+++ b/src/backend/utils/misc/postgresql.conf.sample
@@ -361,7 +361,8 @@
 #log_hostname = off
 #log_line_prefix = ''			# special values:
 					#   %a = application name
-					#   %u = user name
+					#   %u = authenticated user name
+					#   %U = current role name
 					#   %d = database name
 					#   %r = remote host and port
 					#   %h = remote host