control max length of parameter values logged

diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml
index 371d783..b002df5 100644
--- a/doc/src/sgml/config.sgml
+++ b/doc/src/sgml/config.sgml
@@ -6632,6 +6632,24 @@ log_line_prefix = '%m [%p] %q%u@%d/%a '
       </listitem>
      </varlistentry>
 
+     <varlistentry id="guc-log-parameter-max-length" xreflabel="log_parameter_max_length">
+      <term><varname>log_parameter_max_length</varname> (<type>integer</type>)
+      <indexterm>
+       <primary><varname>log_parameter_max_length</varname> configuration parameter</primary>
+      </indexterm>
+      </term>
+      <listitem>
+       <para>
+        If greater than zero, bind parameter values reported in error
+        messages and statement-logging messages are trimmed to no more
+        than this many bytes.
+        If this value is specified without units, it is taken as bytes.
+        Zero (the default) disables trimming.
+        Only superusers can change this setting.
+       </para>
+      </listitem>
+     </varlistentry>
+
      <varlistentry id="guc-log-statement" xreflabel="log_statement">
       <term><varname>log_statement</varname> (<type>enum</type>)
       <indexterm>
diff --git a/src/backend/tcop/postgres.c b/src/backend/tcop/postgres.c
index 9dba3b0..70ce5bb 100644
--- a/src/backend/tcop/postgres.c
+++ b/src/backend/tcop/postgres.c
@@ -1843,13 +1843,24 @@ exec_bind_message(StringInfo input_message)
 						if (knownTextValues == NULL)
 							knownTextValues =
 								palloc0(numParams * sizeof(char *));
-						/*
-						 * Note: must copy at least two more full characters
-						 * than BuildParamLogString wants to see; otherwise it
-						 * might fail to include the ellipsis.
-						 */
-						knownTextValues[paramno] =
-							pnstrdup(pstring, 64 + 2 * MAX_MULTIBYTE_CHAR_LEN);
+
+						if (log_parameter_max_length > 0)
+						{
+							/*
+							 * We can trim the saved string, knowing that we
+							 * won't print all of it.  But we must copy at
+							 * least two more full characters than
+							 * BuildParamLogString wants to use; otherwise it
+							 * might fail to include the trailing ellipsis.
+							 */
+							knownTextValues[paramno] =
+								pnstrdup(pstring,
+										 log_parameter_max_length
+										 + 2 * MAX_MULTIBYTE_CHAR_LEN);
+						}
+						else
+							knownTextValues[paramno] = pstrdup(pstring);
+
 						MemoryContextSwitchTo(oldcxt);
 					}
 					if (pstring != pbuf.data)
@@ -1912,7 +1923,9 @@ exec_bind_message(StringInfo input_message)
 		 */
 		if (log_parameters_on_error)
 			params->paramValuesStr =
-				BuildParamLogString(params, knownTextValues, 64);
+				BuildParamLogString(params,
+									knownTextValues,
+									log_parameter_max_length);
 	}
 	else
 		params = NULL;
@@ -2401,7 +2414,7 @@ errdetail_params(ParamListInfo params)
 	{
 		char   *str;
 
-		str = BuildParamLogString(params, NULL, 0);
+		str = BuildParamLogString(params, NULL, log_parameter_max_length);
 		if (str && str[0] != '\0')
 			errdetail("parameters: %s", str);
 	}
diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c
index 4c6d648..5749aed 100644
--- a/src/backend/utils/misc/guc.c
+++ b/src/backend/utils/misc/guc.c
@@ -544,6 +544,7 @@ int			log_min_messages = WARNING;
 int			client_min_messages = NOTICE;
 int			log_min_duration_sample = -1;
 int			log_min_duration_statement = -1;
+int			log_parameter_max_length = 0;
 int			log_temp_files = -1;
 double		log_statement_sample_rate = 1.0;
 double		log_xact_sample_rate = 0;
@@ -2836,6 +2837,17 @@ static struct config_int ConfigureNamesInt[] =
 	},
 
 	{
+		{"log_parameter_max_length", PGC_SUSET, LOGGING_WHAT,
+			gettext_noop("Limit logged parameter values to first N bytes."),
+			gettext_noop("Zero to print values in full."),
+			GUC_UNIT_BYTE
+		},
+		&log_parameter_max_length,
+		0, 0, INT_MAX / 2,
+		NULL, NULL, NULL
+	},
+
+	{
 		{"bgwriter_delay", PGC_SIGHUP, RESOURCES_BGWRITER,
 			gettext_noop("Background writer sleep time between rounds."),
 			NULL,
diff --git a/src/backend/utils/misc/postgresql.conf.sample b/src/backend/utils/misc/postgresql.conf.sample
index e58e478..e16d63d 100644
--- a/src/backend/utils/misc/postgresql.conf.sample
+++ b/src/backend/utils/misc/postgresql.conf.sample
@@ -546,6 +546,8 @@
 #log_lock_waits = off			# log lock waits >= deadlock_timeout
 #log_statement = 'none'			# none, ddl, mod, all
 #log_parameters_on_error = off	# on error log statements with bind parameters
+#log_parameter_max_length = 0           # limit logged parameter values to
+					# N bytes; 0 means print in full
 #log_replication_commands = off
 #log_temp_files = -1			# log temporary files equal or larger
 					# than the specified size in kilobytes;
diff --git a/src/bin/pgbench/t/001_pgbench_with_server.pl b/src/bin/pgbench/t/001_pgbench_with_server.pl
index 25ea17f..d146e28 100644
--- a/src/bin/pgbench/t/001_pgbench_with_server.pl
+++ b/src/bin/pgbench/t/001_pgbench_with_server.pl
@@ -271,7 +271,9 @@ COMMIT;
 	});
 
 # Verify server logging of parameters.
-$node->append_conf('postgresql.conf', "log_parameters_on_error = true");
+$node->append_conf('postgresql.conf',
+				   "log_parameters_on_error = true\n" .
+				   "log_parameter_max_length = 64");
 $node->reload;
 pgbench(
 		'-n -t1 -c1 -M prepared',
@@ -306,8 +308,8 @@ select column1::jsonb from (values (:value), (:long)) as q;
 ]
 	});
 my $log = TestLib::slurp_file($node->logfile);
-like($log, qr[DETAIL:  parameters: \$1 = '\{ invalid ', \$2 = '''Valame Dios!'' dijo Sancho; ''no le dije yo a vuestra merced que mirase bien lo que hacia\?'''],
-	 "parameter report does not truncate");
+like($log, qr[DETAIL:  parameters: \$1 = '\{ invalid ', \$2 = '''Valame Dios!'' dijo Sancho; ''no le dije yo a vuestra merced que \.\.\.'],
+	 "parameter report truncates");
 $log = undef;
 
 $node->append_conf('postgresql.conf', "log_min_duration_statement = -1");
diff --git a/src/include/utils/guc.h b/src/include/utils/guc.h
index ce93ace..b4186c6 100644
--- a/src/include/utils/guc.h
+++ b/src/include/utils/guc.h
@@ -235,6 +235,7 @@ typedef enum
 /* GUC vars that are actually declared in guc.c, rather than elsewhere */
 extern bool log_duration;
 extern bool log_parameters_on_error;
+extern int	log_parameter_max_length;
 extern bool Debug_print_plan;
 extern bool Debug_print_parse;
 extern bool Debug_print_rewritten;

diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml
index 2de21903a1..35d420e026 100644
--- a/doc/src/sgml/config.sgml
+++ b/doc/src/sgml/config.sgml
@@ -6713,6 +6713,38 @@ log_line_prefix = '%m [%p] %q%u@%d/%a '
       </listitem>
      </varlistentry>
 
+     <varlistentry id="guc-log-parameter-max-length" xreflabel="log_parameter_max_length">
+      <term><varname>log_parameter_max_length</varname> (<type>integer</type>)
+      <indexterm>
+       <primary><varname>log_parameter_max_length</varname> configuration parameter</primary>
+      </indexterm>
+      </term>
+      <listitem>
+       <para>
+        If greater than zero, bind parameter values reported in non-error
+        statement-logging messages are trimmed to no more than this many bytes.
+        If this value is specified without units, it is taken as bytes.
+        Zero (the default) disables trimming. Only superusers can change this setting.
+       </para>
+      </listitem>
+     </varlistentry>
+
+     <varlistentry id="guc-log-parameter-max-length-on-error" xreflabel="log_parameter_max_length_on_error">
+      <term><varname>log_parameter_max_length_on_error</varname> (<type>integer</type>)
+      <indexterm>
+       <primary><varname>log_parameter_max_length_on_error</varname> configuration parameter</primary>
+      </indexterm>
+      </term>
+      <listitem>
+       <para>
+        If greater than zero, bind parameter values reported in error messages
+        are trimmed to no more than this many bytes.
+        If this value is specified without units, it is taken as bytes.
+        Zero (the default) disables trimming.
+       </para>
+      </listitem>
+     </varlistentry>
+
      <varlistentry id="guc-log-statement" xreflabel="log_statement">
       <term><varname>log_statement</varname> (<type>enum</type>)
       <indexterm>
diff --git a/src/backend/tcop/postgres.c b/src/backend/tcop/postgres.c
index 5b677863b9..ea2fe17e0b 100644
--- a/src/backend/tcop/postgres.c
+++ b/src/backend/tcop/postgres.c
@@ -1846,13 +1846,24 @@ exec_bind_message(StringInfo input_message)
 						if (knownTextValues == NULL)
 							knownTextValues =
 								palloc0(numParams * sizeof(char *));
-						/*
-						 * Note: must copy at least two more full characters
-						 * than BuildParamLogString wants to see; otherwise it
-						 * might fail to include the ellipsis.
-						 */
-						knownTextValues[paramno] =
-							pnstrdup(pstring, 64 + 2 * MAX_MULTIBYTE_CHAR_LEN);
+
+						if (log_parameter_max_length_on_error > 0)
+						{
+							/*
+							 * We can trim the saved string, knowing that we
+							 * won't print all of it.  But we must copy at
+							 * least two more full characters than
+							 * BuildParamLogString wants to use; otherwise it
+							 * might fail to include the trailing ellipsis.
+							 */
+							knownTextValues[paramno] =
+								pnstrdup(pstring,
+										 log_parameter_max_length_on_error
+										 + 2 * MAX_MULTIBYTE_CHAR_LEN);
+						}
+						else
+							knownTextValues[paramno] = pstrdup(pstring);
+
 						MemoryContextSwitchTo(oldcxt);
 					}
 					if (pstring != pbuf.data)
@@ -1915,7 +1926,9 @@ exec_bind_message(StringInfo input_message)
 		 */
 		if (log_parameters_on_error)
 			params->paramValuesStr =
-				BuildParamLogString(params, knownTextValues, 64);
+				BuildParamLogString(params,
+									knownTextValues,
+									log_parameter_max_length_on_error);
 	}
 	else
 		params = NULL;
@@ -2404,7 +2417,7 @@ errdetail_params(ParamListInfo params)
 	{
 		char   *str;
 
-		str = BuildParamLogString(params, NULL, 0);
+		str = BuildParamLogString(params, NULL, log_parameter_max_length);
 		if (str && str[0] != '\0')
 			errdetail("parameters: %s", str);
 	}
diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c
index 79bc7ac8ca..a3903d1b16 100644
--- a/src/backend/utils/misc/guc.c
+++ b/src/backend/utils/misc/guc.c
@@ -544,6 +544,8 @@ int			log_min_messages = WARNING;
 int			client_min_messages = NOTICE;
 int			log_min_duration_sample = -1;
 int			log_min_duration_statement = -1;
+int			log_parameter_max_length = 0;
+int			log_parameter_max_length_on_error = 0;
 int			log_temp_files = -1;
 double		log_statement_sample_rate = 1.0;
 double		log_xact_sample_rate = 0;
@@ -2855,6 +2857,28 @@ static struct config_int ConfigureNamesInt[] =
 		NULL, NULL, NULL
 	},
 
+	{
+		{"log_parameter_max_length", PGC_SUSET, LOGGING_WHAT,
+			gettext_noop("When logging statements, limit logged parameter values to first N bytes."),
+			gettext_noop("Zero to print values in full."),
+			GUC_UNIT_BYTE
+		},
+		&log_parameter_max_length,
+		0, 0, INT_MAX / 2,
+		NULL, NULL, NULL
+	},
+
+	{
+		{"log_parameter_max_length_on_error", PGC_USERSET, LOGGING_WHAT,
+			gettext_noop("When reporting an error, limit logged parameter values to first N bytes."),
+			gettext_noop("Zero to print values in full."),
+			GUC_UNIT_BYTE
+		},
+		&log_parameter_max_length_on_error,
+		0, 0, INT_MAX / 2,
+		NULL, NULL, NULL
+	},
+
 	{
 		{"bgwriter_delay", PGC_SIGHUP, RESOURCES_BGWRITER,
 			gettext_noop("Background writer sleep time between rounds."),
diff --git a/src/backend/utils/misc/postgresql.conf.sample b/src/backend/utils/misc/postgresql.conf.sample
index e9f8ca775d..8899f174c7 100644
--- a/src/backend/utils/misc/postgresql.conf.sample
+++ b/src/backend/utils/misc/postgresql.conf.sample
@@ -546,6 +546,10 @@
 #log_lock_waits = off			# log lock waits >= deadlock_timeout
 #log_statement = 'none'			# none, ddl, mod, all
 #log_parameters_on_error = off	# on error log statements with bind parameters
+#log_parameter_max_length = 0   # when logging statements, limit logged
+					# parameter values to N bytes; 0 means print in full
+#log_parameter_max_length_on_error = 0 # when logging an error limit logged
+					# parameter values to N bytes; 0 means print in full
 #log_replication_commands = off
 #log_temp_files = -1			# log temporary files equal or larger
 					# than the specified size in kilobytes;
diff --git a/src/bin/pgbench/t/001_pgbench_with_server.pl b/src/bin/pgbench/t/001_pgbench_with_server.pl
index 25ea17f7d1..1dbdb798c3 100644
--- a/src/bin/pgbench/t/001_pgbench_with_server.pl
+++ b/src/bin/pgbench/t/001_pgbench_with_server.pl
@@ -271,7 +271,10 @@ COMMIT;
 	});
 
 # Verify server logging of parameters.
-$node->append_conf('postgresql.conf', "log_parameters_on_error = true");
+$node->append_conf('postgresql.conf',
+				   "log_parameters_on_error = true\n" .
+				   "log_parameter_max_length = 0\n" .
+				   "log_parameter_max_length_on_error = 64");
 $node->reload;
 pgbench(
 		'-n -t1 -c1 -M prepared',
@@ -287,7 +290,6 @@ pgbench(
 SELECT 1 / (random() / 2)::int, :one::int, :two::int;
 }
 	});
-
 $node->append_conf('postgresql.conf', "log_min_duration_statement = 0");
 $node->reload;
 pgbench(
@@ -310,7 +312,52 @@ like($log, qr[DETAIL:  parameters: \$1 = '\{ invalid ', \$2 = '''Valame Dios!''
 	 "parameter report does not truncate");
 $log = undef;
 
-$node->append_conf('postgresql.conf', "log_min_duration_statement = -1");
+$node->append_conf('postgresql.conf',
+				   "log_min_duration_statement = -1\n" .
+				   "log_parameter_max_length = 7\n" .
+				   "log_parameter_max_length_on_error = 0");
+$node->reload;
+pgbench(
+		'-n -t1 -c1 -M prepared',
+		2,
+		[],
+		[
+		qr{ERROR:  division by zero},
+		qr{CONTEXT:  extended query with parameters: \$1 = '1', \$2 = NULL}
+		],
+		'server parameter logging',
+		{
+			'001_param_3' => q{select '1' as one \gset
+SELECT 1 / (random() / 2)::int, :one::int, :two::int;
+}
+	});
+
+$node->append_conf('postgresql.conf', "log_min_duration_statement = 0");
+$node->reload;
+pgbench(
+		'-n -t1 -c1 -M prepared',
+		2,
+		[],
+		[
+		qr{ERROR:  invalid input syntax for type json},
+		qr[CONTEXT:  JSON data, line 1: \{ invalid\.\.\.[\r\n]+extended query with parameters: \$1 = '\{ invalid ', \$2 = '''Valame Dios!'' dijo Sancho; ''no le dije yo a vuestra merced que mirase bien lo que hacia\?']m
+		],
+		'server parameter logging',
+		{
+			'001_param_4' => q[select '{ invalid ' as value \gset
+select $$'Valame Dios!' dijo Sancho; 'no le dije yo a vuestra merced que mirase bien lo que hacia?'$$ as long \gset
+select column1::jsonb from (values (:value), (:long)) as q;
+]
+	});
+$log = TestLib::slurp_file($node->logfile);
+like($log, qr[DETAIL:  parameters: \$1 = '\{ inval\.\.\.', \$2 = '''Valame\.\.\.'],
+	 "parameter report truncates");
+$log = undef;
+
+$node->append_conf('postgresql.conf',
+				   "log_parameter_max_length = 0\n" .
+				   "log_min_duration_statement = -1\n" .
+				   "log_parameters_on_error = false");
 $node->reload;
 
 # test expressions
diff --git a/src/include/utils/guc.h b/src/include/utils/guc.h
index ce93ace76c..e314552cb8 100644
--- a/src/include/utils/guc.h
+++ b/src/include/utils/guc.h
@@ -235,6 +235,8 @@ typedef enum
 /* GUC vars that are actually declared in guc.c, rather than elsewhere */
 extern bool log_duration;
 extern bool log_parameters_on_error;
+extern int	log_parameter_max_length;
+extern int	log_parameter_max_length_on_error;
 extern bool Debug_print_plan;
 extern bool Debug_print_parse;
 extern bool Debug_print_rewritten;

diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml
index 2de21903a1..3d7db57d74 100644
--- a/doc/src/sgml/config.sgml
+++ b/doc/src/sgml/config.sgml
@@ -6690,29 +6690,48 @@ log_line_prefix = '%m [%p] %q%u@%d/%a '
       </listitem>
      </varlistentry>
 
-     <varlistentry id="guc-log-parameters-on-error" xreflabel="log_parameters_on_error">
-      <term><varname>log_parameters_on_error</varname> (<type>boolean</type>)
+     <varlistentry id="guc-log-parameter-max-length" xreflabel="log_parameter_max_length">
+      <term><varname>log_parameter_max_length</varname> (<type>integer</type>)
       <indexterm>
-       <primary><varname>log_parameters_on_error</varname> configuration parameter</primary>
+       <primary><varname>log_parameter_max_length</varname> configuration parameter</primary>
       </indexterm>
       </term>
       <listitem>
        <para>
-        Controls whether bind parameters are logged when a statement is logged
-        as a result of <xref linkend="guc-log-min-error-statement"/>.
-        It adds some overhead, as <productname>PostgreSQL</productname> will
-        compute and store textual representations of parameter values in
-        memory for all statements, even if they eventually do not get logged.
-        This setting has no effect on statements logged due to
-        <xref linkend="guc-log-min-duration-statement"/> or
-        <xref linkend="guc-log-statement"/> settings, as they are always logged
-        with parameters.
-        The default is <literal>off</literal>.
+        If greater than zero, bind parameter values reported in non-error
+        statement-logging messages are trimmed to no more than this many bytes.
+        If this value is specified without units, it is taken as bytes.
+        Zero disables logging parameters with statements.
+        <literal>-1</literal> (the default) makes parameters logged in full.
         Only superusers can change this setting.
        </para>
       </listitem>
      </varlistentry>
 
+     <varlistentry id="guc-log-parameter-max-length-on-error" xreflabel="log_parameter_max_length_on_error">
+      <term><varname>log_parameter_max_length_on_error</varname> (<type>integer</type>)
+      <indexterm>
+       <primary><varname>log_parameter_max_length_on_error</varname> configuration parameter</primary>
+      </indexterm>
+      </term>
+      <listitem>
+       <para>
+        If greater than zero, bind parameter values reported in error messages
+        are trimmed to no more than this many bytes.
+        If this value is specified without units, it is taken as bytes.
+        Zero (the default) disables logging parameters on error.        
+        <literal>-1</literal> makes parameters logged in full.
+        
+        This setting only affects statements logged as a result of
+        <xref linkend="guc-log-min-error-statement"/>.
+        Non-zero values add some overhead, as
+        <productname>PostgreSQL</productname> will compute and store textual
+        representations of parameter values in memory for all statements,
+        even if they eventually do not get logged.        
+       </para>
+      </listitem>
+     </varlistentry>
+
      <varlistentry id="guc-log-statement" xreflabel="log_statement">
       <term><varname>log_statement</varname> (<type>enum</type>)
       <indexterm>
diff --git a/src/backend/nodes/params.c b/src/backend/nodes/params.c
index a57f9eea76..77328e17ff 100644
--- a/src/backend/nodes/params.c
+++ b/src/backend/nodes/params.c
@@ -269,7 +269,7 @@ RestoreParamList(char **start_address)
  * can contain NULLs for any unknown individual values.  NULL can be given if
  * no parameters are known.
  *
- * If maxlen is not zero, that's the maximum number of bytes of any one
+ * If maxlen is not -1, that's the maximum number of bytes of any one
  * parameter value to be printed; an ellipsis is added if the string is
  * longer.  (Added quotes are not considered in this calculation.)
  */
@@ -280,6 +280,7 @@ BuildParamLogString(ParamListInfo params, char **knownTextValues, int maxlen)
 				oldCxt;
 	StringInfoData buf;
 
+	Assert(maxlen == -1 || maxlen > 0);
 	/*
 	 * NB: think not of returning params->paramValuesStr!  It may have been
 	 * generated with a different maxlen, and so be unsuitable.  Besides that,
diff --git a/src/backend/tcop/postgres.c b/src/backend/tcop/postgres.c
index 5b677863b9..cbe4907e61 100644
--- a/src/backend/tcop/postgres.c
+++ b/src/backend/tcop/postgres.c
@@ -1838,7 +1838,7 @@ exec_bind_message(StringInfo input_message)
 				 */
 				if (pstring)
 				{
-					if (log_parameters_on_error)
+					if (log_parameter_max_length_on_error != 0)
 					{
 						MemoryContext	oldcxt;
 
@@ -1846,13 +1846,24 @@ exec_bind_message(StringInfo input_message)
 						if (knownTextValues == NULL)
 							knownTextValues =
 								palloc0(numParams * sizeof(char *));
-						/*
-						 * Note: must copy at least two more full characters
-						 * than BuildParamLogString wants to see; otherwise it
-						 * might fail to include the ellipsis.
-						 */
-						knownTextValues[paramno] =
-							pnstrdup(pstring, 64 + 2 * MAX_MULTIBYTE_CHAR_LEN);
+
+						if (log_parameter_max_length_on_error > 0)
+						{
+							/*
+							 * We can trim the saved string, knowing that we
+							 * won't print all of it.  But we must copy at
+							 * least two more full characters than
+							 * BuildParamLogString wants to use; otherwise it
+							 * might fail to include the trailing ellipsis.
+							 */
+							knownTextValues[paramno] =
+								pnstrdup(pstring,
+										 log_parameter_max_length_on_error
+										 + 2 * MAX_MULTIBYTE_CHAR_LEN);
+						}
+						else
+							knownTextValues[paramno] = pstrdup(pstring);
+
 						MemoryContextSwitchTo(oldcxt);
 					}
 					if (pstring != pbuf.data)
@@ -1913,9 +1924,11 @@ exec_bind_message(StringInfo input_message)
 		 * errors, if configured to do so.  (This is saved in the portal, so
 		 * that they'll appear when the query is executed later.)
 		 */
-		if (log_parameters_on_error)
+		if (log_parameter_max_length_on_error != 0)
 			params->paramValuesStr =
-				BuildParamLogString(params, knownTextValues, 64);
+				BuildParamLogString(params,
+									knownTextValues,
+									log_parameter_max_length_on_error);
 	}
 	else
 		params = NULL;
@@ -2400,11 +2413,11 @@ errdetail_execute(List *raw_parsetree_list)
 static int
 errdetail_params(ParamListInfo params)
 {
-	if (params && params->numParams > 0)
+	if (log_parameter_max_length != 0 && params && params->numParams > 0)
 	{
 		char   *str;
 
-		str = BuildParamLogString(params, NULL, 0);
+		str = BuildParamLogString(params, NULL, log_parameter_max_length);
 		if (str && str[0] != '\0')
 			errdetail("parameters: %s", str);
 	}
diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c
index 79bc7ac8ca..538d940895 100644
--- a/src/backend/utils/misc/guc.c
+++ b/src/backend/utils/misc/guc.c
@@ -515,7 +515,6 @@ extern const struct config_enum_entry dynamic_shared_memory_options[];
  * GUC option variables that are exported from this module
  */
 bool		log_duration = false;
-bool		log_parameters_on_error = false;
 bool		Debug_print_plan = false;
 bool		Debug_print_parse = false;
 bool		Debug_print_rewritten = false;
@@ -544,6 +543,8 @@ int			log_min_messages = WARNING;
 int			client_min_messages = NOTICE;
 int			log_min_duration_sample = -1;
 int			log_min_duration_statement = -1;
+int			log_parameter_max_length = 0;
+int			log_parameter_max_length_on_error = 0;
 int			log_temp_files = -1;
 double		log_statement_sample_rate = 1.0;
 double		log_xact_sample_rate = 0;
@@ -1381,15 +1382,6 @@ static struct config_bool ConfigureNamesBool[] =
 		false,
 		NULL, NULL, NULL
 	},
-	{
-		{"log_parameters_on_error", PGC_SUSET, LOGGING_WHAT,
-			gettext_noop("Logs bind parameters of the logged statements where possible."),
-			NULL
-		},
-		&log_parameters_on_error,
-		false,
-		NULL, NULL, NULL
-	},
 	{
 		{"debug_print_parse", PGC_USERSET, LOGGING_WHAT,
 			gettext_noop("Logs each query's parse tree."),
@@ -2855,6 +2847,28 @@ static struct config_int ConfigureNamesInt[] =
 		NULL, NULL, NULL
 	},
 
+	{
+		{"log_parameter_max_length", PGC_SUSET, LOGGING_WHAT,
+			gettext_noop("When logging statements, limit logged parameter values to first N bytes."),
+			gettext_noop("Zero to print values in full."),
+			GUC_UNIT_BYTE
+		},
+		&log_parameter_max_length,
+		-1, -1, INT_MAX / 2,
+		NULL, NULL, NULL
+	},
+
+	{
+		{"log_parameter_max_length_on_error", PGC_USERSET, LOGGING_WHAT,
+			gettext_noop("When reporting an error, limit logged parameter values to first N bytes."),
+			gettext_noop("Zero to print values in full."),
+			GUC_UNIT_BYTE
+		},
+		&log_parameter_max_length_on_error,
+		0, -1, INT_MAX / 2,
+		NULL, NULL, NULL
+	},
+
 	{
 		{"bgwriter_delay", PGC_SIGHUP, RESOURCES_BGWRITER,
 			gettext_noop("Background writer sleep time between rounds."),
diff --git a/src/backend/utils/misc/postgresql.conf.sample b/src/backend/utils/misc/postgresql.conf.sample
index e9f8ca775d..8c26ac90d1 100644
--- a/src/backend/utils/misc/postgresql.conf.sample
+++ b/src/backend/utils/misc/postgresql.conf.sample
@@ -545,7 +545,12 @@
 					# e.g. '<%u%%%d> '
 #log_lock_waits = off			# log lock waits >= deadlock_timeout
 #log_statement = 'none'			# none, ddl, mod, all
-#log_parameters_on_error = off	# on error log statements with bind parameters
+#log_parameter_max_length = -1   # when logging statements, limit logged
+					# parameter values to N bytes;
+					# -1 means print in full, 0 to disable
+#log_parameter_max_length_on_error = 0 # when logging an error, limit logged
+					# parameter values to N bytes;
+					# -1 means print in full, 0 to disable
 #log_replication_commands = off
 #log_temp_files = -1			# log temporary files equal or larger
 					# than the specified size in kilobytes;
diff --git a/src/bin/pgbench/t/001_pgbench_with_server.pl b/src/bin/pgbench/t/001_pgbench_with_server.pl
index 25ea17f7d1..b7eb37d65d 100644
--- a/src/bin/pgbench/t/001_pgbench_with_server.pl
+++ b/src/bin/pgbench/t/001_pgbench_with_server.pl
@@ -271,7 +271,35 @@ COMMIT;
 	});
 
 # Verify server logging of parameters.
-$node->append_conf('postgresql.conf', "log_parameters_on_error = true");
+# 1. Logging neither with errors nor with statements
+$node->append_conf('postgresql.conf',
+				   "log_min_duration_statement = 0\n" .
+				   "log_parameter_max_length = 0\n" .
+				   "log_parameter_max_length_on_error = 0");
+$node->reload;
+pgbench(
+		'-n -t1 -c1 -M prepared',
+		2,
+		[],
+		[
+		qr{ERROR:  invalid input syntax for type json},
+		qr{(?!extended query with parameters)}
+		],
+		'server parameter logging',
+		{
+			'001_param_1' => q[select '{ invalid ' as value \gset
+select $$'Valame Dios!' dijo Sancho; 'no le dije yo a vuestra merced que mirase bien lo que hacia?'$$ as long \gset
+select column1::jsonb from (values (:value), (:long)) as q;
+]
+	});
+my $log = TestLib::slurp_file($node->logfile);
+unlike($log, qr[DETAIL:  parameters: \$1 = '\{ invalid ',], "no parameters logged");
+$log = undef;
+
+# 2. Logging truncated parameters on error, full with statements
+$node->append_conf('postgresql.conf',
+				   "log_parameter_max_length = -1\n" .
+				   "log_parameter_max_length_on_error = 64");
 $node->reload;
 pgbench(
 		'-n -t1 -c1 -M prepared',
@@ -283,11 +311,10 @@ pgbench(
 		],
 		'server parameter logging',
 		{
-			'001_param_1' => q{select '1' as one \gset
+			'001_param_2' => q{select '1' as one \gset
 SELECT 1 / (random() / 2)::int, :one::int, :two::int;
 }
 	});
-
 $node->append_conf('postgresql.conf', "log_min_duration_statement = 0");
 $node->reload;
 pgbench(
@@ -300,17 +327,64 @@ pgbench(
 		],
 		'server parameter logging',
 		{
-			'001_param_2' => q[select '{ invalid ' as value \gset
+			'001_param_3' => q[select '{ invalid ' as value \gset
 select $$'Valame Dios!' dijo Sancho; 'no le dije yo a vuestra merced que mirase bien lo que hacia?'$$ as long \gset
 select column1::jsonb from (values (:value), (:long)) as q;
 ]
 	});
-my $log = TestLib::slurp_file($node->logfile);
+$log = TestLib::slurp_file($node->logfile);
 like($log, qr[DETAIL:  parameters: \$1 = '\{ invalid ', \$2 = '''Valame Dios!'' dijo Sancho; ''no le dije yo a vuestra merced que mirase bien lo que hacia\?'''],
 	 "parameter report does not truncate");
 $log = undef;
 
-$node->append_conf('postgresql.conf', "log_min_duration_statement = -1");
+# 3. Logging full parameters on error, truncated with statements
+$node->append_conf('postgresql.conf',
+				   "log_min_duration_statement = -1\n" .
+				   "log_parameter_max_length = 7\n" .
+				   "log_parameter_max_length_on_error = -1");
+$node->reload;
+pgbench(
+		'-n -t1 -c1 -M prepared',
+		2,
+		[],
+		[
+		qr{ERROR:  division by zero},
+		qr{CONTEXT:  extended query with parameters: \$1 = '1', \$2 = NULL}
+		],
+		'server parameter logging',
+		{
+			'001_param_4' => q{select '1' as one \gset
+SELECT 1 / (random() / 2)::int, :one::int, :two::int;
+}
+	});
+
+$node->append_conf('postgresql.conf', "log_min_duration_statement = 0");
+$node->reload;
+pgbench(
+		'-n -t1 -c1 -M prepared',
+		2,
+		[],
+		[
+		qr{ERROR:  invalid input syntax for type json},
+		qr[CONTEXT:  JSON data, line 1: \{ invalid\.\.\.[\r\n]+extended query with parameters: \$1 = '\{ invalid ', \$2 = '''Valame Dios!'' dijo Sancho; ''no le dije yo a vuestra merced que mirase bien lo que hacia\?']m
+		],
+		'server parameter logging',
+		{
+			'001_param_5' => q[select '{ invalid ' as value \gset
+select $$'Valame Dios!' dijo Sancho; 'no le dije yo a vuestra merced que mirase bien lo que hacia?'$$ as long \gset
+select column1::jsonb from (values (:value), (:long)) as q;
+]
+	});
+$log = TestLib::slurp_file($node->logfile);
+like($log, qr[DETAIL:  parameters: \$1 = '\{ inval\.\.\.', \$2 = '''Valame\.\.\.'],
+	 "parameter report truncates");
+$log = undef;
+
+# 3. Restore config
+$node->append_conf('postgresql.conf',
+				   "log_min_duration_statement = -1\n" .
+				   "log_parameter_max_length_on_error = 0\n" .
+				   "log_parameter_max_length = -1");
 $node->reload;
 
 # test expressions
diff --git a/src/include/utils/guc.h b/src/include/utils/guc.h
index ce93ace76c..a375914440 100644
--- a/src/include/utils/guc.h
+++ b/src/include/utils/guc.h
@@ -234,7 +234,8 @@ typedef enum
 
 /* GUC vars that are actually declared in guc.c, rather than elsewhere */
 extern bool log_duration;
-extern bool log_parameters_on_error;
+extern int	log_parameter_max_length;
+extern int	log_parameter_max_length_on_error;
 extern bool Debug_print_plan;
 extern bool Debug_print_parse;
 extern bool Debug_print_rewritten;

diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml
index 2de21903a1..21b65f2791 100644
--- a/doc/src/sgml/config.sgml
+++ b/doc/src/sgml/config.sgml
@@ -6690,29 +6690,47 @@ log_line_prefix = '%m [%p] %q%u@%d/%a '
       </listitem>
      </varlistentry>
 
-     <varlistentry id="guc-log-parameters-on-error" xreflabel="log_parameters_on_error">
-      <term><varname>log_parameters_on_error</varname> (<type>boolean</type>)
+     <varlistentry id="guc-log-parameter-max-length" xreflabel="log_parameter_max_length">
+      <term><varname>log_parameter_max_length</varname> (<type>integer</type>)
       <indexterm>
-       <primary><varname>log_parameters_on_error</varname> configuration parameter</primary>
+       <primary><varname>log_parameter_max_length</varname> configuration parameter</primary>
       </indexterm>
       </term>
       <listitem>
        <para>
-        Controls whether bind parameters are logged when a statement is logged
-        as a result of <xref linkend="guc-log-min-error-statement"/>.
-        It adds some overhead, as <productname>PostgreSQL</productname> will
-        compute and store textual representations of parameter values in
-        memory for all statements, even if they eventually do not get logged.
-        This setting has no effect on statements logged due to
-        <xref linkend="guc-log-min-duration-statement"/> or
-        <xref linkend="guc-log-statement"/> settings, as they are always logged
-        with parameters.
-        The default is <literal>off</literal>.
+        If greater than zero, each bind parameter value reported in non-error
+        statement-logging messages is trimmed to this many bytes.
+        If this value is specified without units, it is taken as bytes.
+        Zero disables logging parameters with statements.
+        <literal>-1</literal> (the default) makes parameters logged in full.
         Only superusers can change this setting.
        </para>
       </listitem>
      </varlistentry>
 
+     <varlistentry id="guc-log-parameter-max-length-on-error" xreflabel="log_parameter_max_length_on_error">
+      <term><varname>log_parameter_max_length_on_error</varname> (<type>integer</type>)
+      <indexterm>
+       <primary><varname>log_parameter_max_length_on_error</varname> configuration parameter</primary>
+      </indexterm>
+      </term>
+      <listitem>
+       <para>
+        If greater than zero, each bind parameter value reported in error messages
+        is trimmed to this many bytes. If this value is specified without units,
+        it is taken as bytes. Zero (the default) disables logging parameters on error.        
+        <literal>-1</literal> causes parameters logged in full.
+        
+        This setting only affects statements logged as a result of
+        <xref linkend="guc-log-min-error-statement"/>.
+        Non-zero values add some overhead, as
+        <productname>PostgreSQL</productname> will compute and store textual
+        representations of parameter values in memory for all statements,
+        even if they eventually do not get logged.        
+       </para>
+      </listitem>
+     </varlistentry>
+
      <varlistentry id="guc-log-statement" xreflabel="log_statement">
       <term><varname>log_statement</varname> (<type>enum</type>)
       <indexterm>
diff --git a/src/backend/nodes/params.c b/src/backend/nodes/params.c
index a57f9eea76..77328e17ff 100644
--- a/src/backend/nodes/params.c
+++ b/src/backend/nodes/params.c
@@ -269,7 +269,7 @@ RestoreParamList(char **start_address)
  * can contain NULLs for any unknown individual values.  NULL can be given if
  * no parameters are known.
  *
- * If maxlen is not zero, that's the maximum number of bytes of any one
+ * If maxlen is not -1, that's the maximum number of bytes of any one
  * parameter value to be printed; an ellipsis is added if the string is
  * longer.  (Added quotes are not considered in this calculation.)
  */
@@ -280,6 +280,7 @@ BuildParamLogString(ParamListInfo params, char **knownTextValues, int maxlen)
 				oldCxt;
 	StringInfoData buf;
 
+	Assert(maxlen == -1 || maxlen > 0);
 	/*
 	 * NB: think not of returning params->paramValuesStr!  It may have been
 	 * generated with a different maxlen, and so be unsuitable.  Besides that,
diff --git a/src/backend/tcop/postgres.c b/src/backend/tcop/postgres.c
index 5b677863b9..f185935d0a 100644
--- a/src/backend/tcop/postgres.c
+++ b/src/backend/tcop/postgres.c
@@ -1838,7 +1838,7 @@ exec_bind_message(StringInfo input_message)
 				 */
 				if (pstring)
 				{
-					if (log_parameters_on_error)
+					if (log_parameter_max_length_on_error != 0)
 					{
 						MemoryContext	oldcxt;
 
@@ -1846,13 +1846,24 @@ exec_bind_message(StringInfo input_message)
 						if (knownTextValues == NULL)
 							knownTextValues =
 								palloc0(numParams * sizeof(char *));
-						/*
-						 * Note: must copy at least two more full characters
-						 * than BuildParamLogString wants to see; otherwise it
-						 * might fail to include the ellipsis.
-						 */
-						knownTextValues[paramno] =
-							pnstrdup(pstring, 64 + 2 * MAX_MULTIBYTE_CHAR_LEN);
+
+						if (log_parameter_max_length_on_error == -1)
+							knownTextValues[paramno] = pstrdup(pstring);
+						else
+						{
+							/*
+							 * We can trim the saved string, knowing that we
+							 * won't print all of it.  But we must copy at
+							 * least two more full characters than
+							 * BuildParamLogString wants to use; otherwise it
+							 * might fail to include the trailing ellipsis.
+							 */
+							knownTextValues[paramno] =
+								pnstrdup(pstring,
+										 log_parameter_max_length_on_error
+										 + 2 * MAX_MULTIBYTE_CHAR_LEN);
+						}
+
 						MemoryContextSwitchTo(oldcxt);
 					}
 					if (pstring != pbuf.data)
@@ -1913,9 +1924,11 @@ exec_bind_message(StringInfo input_message)
 		 * errors, if configured to do so.  (This is saved in the portal, so
 		 * that they'll appear when the query is executed later.)
 		 */
-		if (log_parameters_on_error)
+		if (log_parameter_max_length_on_error != 0)
 			params->paramValuesStr =
-				BuildParamLogString(params, knownTextValues, 64);
+				BuildParamLogString(params,
+									knownTextValues,
+									log_parameter_max_length_on_error);
 	}
 	else
 		params = NULL;
@@ -2400,11 +2413,11 @@ errdetail_execute(List *raw_parsetree_list)
 static int
 errdetail_params(ParamListInfo params)
 {
-	if (params && params->numParams > 0)
+	if (log_parameter_max_length != 0 && params && params->numParams > 0)
 	{
 		char   *str;
 
-		str = BuildParamLogString(params, NULL, 0);
+		str = BuildParamLogString(params, NULL, log_parameter_max_length);
 		if (str && str[0] != '\0')
 			errdetail("parameters: %s", str);
 	}
diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c
index 79bc7ac8ca..538d940895 100644
--- a/src/backend/utils/misc/guc.c
+++ b/src/backend/utils/misc/guc.c
@@ -515,7 +515,6 @@ extern const struct config_enum_entry dynamic_shared_memory_options[];
  * GUC option variables that are exported from this module
  */
 bool		log_duration = false;
-bool		log_parameters_on_error = false;
 bool		Debug_print_plan = false;
 bool		Debug_print_parse = false;
 bool		Debug_print_rewritten = false;
@@ -544,6 +543,8 @@ int			log_min_messages = WARNING;
 int			client_min_messages = NOTICE;
 int			log_min_duration_sample = -1;
 int			log_min_duration_statement = -1;
+int			log_parameter_max_length = 0;
+int			log_parameter_max_length_on_error = 0;
 int			log_temp_files = -1;
 double		log_statement_sample_rate = 1.0;
 double		log_xact_sample_rate = 0;
@@ -1381,15 +1382,6 @@ static struct config_bool ConfigureNamesBool[] =
 		false,
 		NULL, NULL, NULL
 	},
-	{
-		{"log_parameters_on_error", PGC_SUSET, LOGGING_WHAT,
-			gettext_noop("Logs bind parameters of the logged statements where possible."),
-			NULL
-		},
-		&log_parameters_on_error,
-		false,
-		NULL, NULL, NULL
-	},
 	{
 		{"debug_print_parse", PGC_USERSET, LOGGING_WHAT,
 			gettext_noop("Logs each query's parse tree."),
@@ -2855,6 +2847,28 @@ static struct config_int ConfigureNamesInt[] =
 		NULL, NULL, NULL
 	},
 
+	{
+		{"log_parameter_max_length", PGC_SUSET, LOGGING_WHAT,
+			gettext_noop("When logging statements, limit logged parameter values to first N bytes."),
+			gettext_noop("Zero to print values in full."),
+			GUC_UNIT_BYTE
+		},
+		&log_parameter_max_length,
+		-1, -1, INT_MAX / 2,
+		NULL, NULL, NULL
+	},
+
+	{
+		{"log_parameter_max_length_on_error", PGC_USERSET, LOGGING_WHAT,
+			gettext_noop("When reporting an error, limit logged parameter values to first N bytes."),
+			gettext_noop("Zero to print values in full."),
+			GUC_UNIT_BYTE
+		},
+		&log_parameter_max_length_on_error,
+		0, -1, INT_MAX / 2,
+		NULL, NULL, NULL
+	},
+
 	{
 		{"bgwriter_delay", PGC_SIGHUP, RESOURCES_BGWRITER,
 			gettext_noop("Background writer sleep time between rounds."),
diff --git a/src/backend/utils/misc/postgresql.conf.sample b/src/backend/utils/misc/postgresql.conf.sample
index e9f8ca775d..8c26ac90d1 100644
--- a/src/backend/utils/misc/postgresql.conf.sample
+++ b/src/backend/utils/misc/postgresql.conf.sample
@@ -545,7 +545,12 @@
 					# e.g. '<%u%%%d> '
 #log_lock_waits = off			# log lock waits >= deadlock_timeout
 #log_statement = 'none'			# none, ddl, mod, all
-#log_parameters_on_error = off	# on error log statements with bind parameters
+#log_parameter_max_length = -1   # when logging statements, limit logged
+					# parameter values to N bytes;
+					# -1 means print in full, 0 to disable
+#log_parameter_max_length_on_error = 0 # when logging an error, limit logged
+					# parameter values to N bytes;
+					# -1 means print in full, 0 to disable
 #log_replication_commands = off
 #log_temp_files = -1			# log temporary files equal or larger
 					# than the specified size in kilobytes;
diff --git a/src/bin/pgbench/t/001_pgbench_with_server.pl b/src/bin/pgbench/t/001_pgbench_with_server.pl
index 25ea17f7d1..b7eb37d65d 100644
--- a/src/bin/pgbench/t/001_pgbench_with_server.pl
+++ b/src/bin/pgbench/t/001_pgbench_with_server.pl
@@ -271,7 +271,35 @@ COMMIT;
 	});
 
 # Verify server logging of parameters.
-$node->append_conf('postgresql.conf', "log_parameters_on_error = true");
+# 1. Logging neither with errors nor with statements
+$node->append_conf('postgresql.conf',
+				   "log_min_duration_statement = 0\n" .
+				   "log_parameter_max_length = 0\n" .
+				   "log_parameter_max_length_on_error = 0");
+$node->reload;
+pgbench(
+		'-n -t1 -c1 -M prepared',
+		2,
+		[],
+		[
+		qr{ERROR:  invalid input syntax for type json},
+		qr{(?!extended query with parameters)}
+		],
+		'server parameter logging',
+		{
+			'001_param_1' => q[select '{ invalid ' as value \gset
+select $$'Valame Dios!' dijo Sancho; 'no le dije yo a vuestra merced que mirase bien lo que hacia?'$$ as long \gset
+select column1::jsonb from (values (:value), (:long)) as q;
+]
+	});
+my $log = TestLib::slurp_file($node->logfile);
+unlike($log, qr[DETAIL:  parameters: \$1 = '\{ invalid ',], "no parameters logged");
+$log = undef;
+
+# 2. Logging truncated parameters on error, full with statements
+$node->append_conf('postgresql.conf',
+				   "log_parameter_max_length = -1\n" .
+				   "log_parameter_max_length_on_error = 64");
 $node->reload;
 pgbench(
 		'-n -t1 -c1 -M prepared',
@@ -283,11 +311,10 @@ pgbench(
 		],
 		'server parameter logging',
 		{
-			'001_param_1' => q{select '1' as one \gset
+			'001_param_2' => q{select '1' as one \gset
 SELECT 1 / (random() / 2)::int, :one::int, :two::int;
 }
 	});
-
 $node->append_conf('postgresql.conf', "log_min_duration_statement = 0");
 $node->reload;
 pgbench(
@@ -300,17 +327,64 @@ pgbench(
 		],
 		'server parameter logging',
 		{
-			'001_param_2' => q[select '{ invalid ' as value \gset
+			'001_param_3' => q[select '{ invalid ' as value \gset
 select $$'Valame Dios!' dijo Sancho; 'no le dije yo a vuestra merced que mirase bien lo que hacia?'$$ as long \gset
 select column1::jsonb from (values (:value), (:long)) as q;
 ]
 	});
-my $log = TestLib::slurp_file($node->logfile);
+$log = TestLib::slurp_file($node->logfile);
 like($log, qr[DETAIL:  parameters: \$1 = '\{ invalid ', \$2 = '''Valame Dios!'' dijo Sancho; ''no le dije yo a vuestra merced que mirase bien lo que hacia\?'''],
 	 "parameter report does not truncate");
 $log = undef;
 
-$node->append_conf('postgresql.conf', "log_min_duration_statement = -1");
+# 3. Logging full parameters on error, truncated with statements
+$node->append_conf('postgresql.conf',
+				   "log_min_duration_statement = -1\n" .
+				   "log_parameter_max_length = 7\n" .
+				   "log_parameter_max_length_on_error = -1");
+$node->reload;
+pgbench(
+		'-n -t1 -c1 -M prepared',
+		2,
+		[],
+		[
+		qr{ERROR:  division by zero},
+		qr{CONTEXT:  extended query with parameters: \$1 = '1', \$2 = NULL}
+		],
+		'server parameter logging',
+		{
+			'001_param_4' => q{select '1' as one \gset
+SELECT 1 / (random() / 2)::int, :one::int, :two::int;
+}
+	});
+
+$node->append_conf('postgresql.conf', "log_min_duration_statement = 0");
+$node->reload;
+pgbench(
+		'-n -t1 -c1 -M prepared',
+		2,
+		[],
+		[
+		qr{ERROR:  invalid input syntax for type json},
+		qr[CONTEXT:  JSON data, line 1: \{ invalid\.\.\.[\r\n]+extended query with parameters: \$1 = '\{ invalid ', \$2 = '''Valame Dios!'' dijo Sancho; ''no le dije yo a vuestra merced que mirase bien lo que hacia\?']m
+		],
+		'server parameter logging',
+		{
+			'001_param_5' => q[select '{ invalid ' as value \gset
+select $$'Valame Dios!' dijo Sancho; 'no le dije yo a vuestra merced que mirase bien lo que hacia?'$$ as long \gset
+select column1::jsonb from (values (:value), (:long)) as q;
+]
+	});
+$log = TestLib::slurp_file($node->logfile);
+like($log, qr[DETAIL:  parameters: \$1 = '\{ inval\.\.\.', \$2 = '''Valame\.\.\.'],
+	 "parameter report truncates");
+$log = undef;
+
+# 3. Restore config
+$node->append_conf('postgresql.conf',
+				   "log_min_duration_statement = -1\n" .
+				   "log_parameter_max_length_on_error = 0\n" .
+				   "log_parameter_max_length = -1");
 $node->reload;
 
 # test expressions
diff --git a/src/include/utils/guc.h b/src/include/utils/guc.h
index ce93ace76c..a375914440 100644
--- a/src/include/utils/guc.h
+++ b/src/include/utils/guc.h
@@ -234,7 +234,8 @@ typedef enum
 
 /* GUC vars that are actually declared in guc.c, rather than elsewhere */
 extern bool log_duration;
-extern bool log_parameters_on_error;
+extern int	log_parameter_max_length;
+extern int	log_parameter_max_length_on_error;
 extern bool Debug_print_plan;
 extern bool Debug_print_parse;
 extern bool Debug_print_rewritten;