*** a/src/backend/nodes/makefuncs.c
--- b/src/backend/nodes/makefuncs.c
***************
*** 17,24 ****
--- 17,26 ----
  
  #include "catalog/pg_type.h"
  #include "nodes/makefuncs.h"
+ #include "utils/builtins.h"
  #include "utils/lsyscache.h"
  
+ static bool parseBooleanGenericOption(DefElem *opt);
  
  /*
   * makeA_Expr -
***************
*** 385,387 **** makeDefElemExtended(char *namespace, char *name, Node *arg,
--- 387,435 ----
  
  	return res;
  }
+ 
+ /*
+  * makeExplain -
+  *  build an ExplainStmt node by parsing the generic options list
+  */
+ ExplainStmt *
+ makeExplain(List *options, Node *query)
+ {
+ 	ExplainStmt *n = makeNode(ExplainStmt);
+ 	ListCell *lc;
+ 
+ 	foreach (lc, options)
+ 	{
+ 		DefElem *opt = lfirst(lc);
+ 		if (!strcmp(opt->defname, "analyze"))
+ 			n->analyze = parseBooleanGenericOption(opt);
+ 		else if (!strcmp(opt->defname, "verbose"))
+ 			n->verbose = parseBooleanGenericOption(opt);
+ 		else
+ 			ereport(ERROR,
+ 				(errcode(ERRCODE_UNDEFINED_PARAMETER),
+ 				 errmsg("unknown EXPLAIN option: %s", opt->defname)));
+ 	}
+ 
+ 	n->query = query;
+ 	return n;
+ }
+ 
+ /*
+  * parseBooleanGenericOption -
+  * 	Interpret a generic option as a boolean.  Currently, a generic_option_arg
+  * 	can only be a string, so we don't need to worry about anything else.
+  */
+ static bool
+ parseBooleanGenericOption(DefElem *opt)
+ {
+ 	bool res;
+ 
+ 	Assert(IsA(opt->arg, String));
+ 	if (!parse_bool(strVal(opt->arg), &res))
+ 		ereport(ERROR,
+ 			(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ 			 errmsg("parameter \"%s\" requires a Boolean value",
+ 				opt->defname)));
+ 	return res;
+ }
*** a/src/backend/parser/gram.y
--- b/src/backend/parser/gram.y
***************
*** 6436,6452 **** opt_name_list:
   *
   *		QUERY:
   *				EXPLAIN [ANALYZE] [VERBOSE] query
   *
   *****************************************************************************/
  
  ExplainStmt: EXPLAIN opt_analyze opt_verbose ExplainableStmt
  				{
! 					ExplainStmt *n = makeNode(ExplainStmt);
  					n->analyze = $2;
  					n->verbose = $3;
- 					n->query = $4;
  					$$ = (Node *)n;
  				}
  		;
  
  ExplainableStmt:
--- 6436,6456 ----
   *
   *		QUERY:
   *				EXPLAIN [ANALYZE] [VERBOSE] query
+  *				EXPLAIN ( generic options ) query
   *
   *****************************************************************************/
  
  ExplainStmt: EXPLAIN opt_analyze opt_verbose ExplainableStmt
  				{
! 					ExplainStmt *n = makeExplain(NIL, (Node *) $4);
  					n->analyze = $2;
  					n->verbose = $3;
  					$$ = (Node *)n;
  				}
+ 		|	EXPLAIN '(' generic_option_list ')' ExplainableStmt
+ 				{
+ 					$$ = (Node *) makeExplain((List *) $3, (Node *) $5);
+ 				}
  		;
  
  ExplainableStmt:
***************
*** 6459,6467 **** ExplainableStmt:
  			| ExecuteStmt					/* by default all are $$=$1 */
  		;
  
  opt_analyze:
  			analyze_keyword			{ $$ = TRUE; }
! 			| /* EMPTY */			{ $$ = FALSE; }
  		;
  
  /*****************************************************************************
--- 6463,6484 ----
  			| ExecuteStmt					/* by default all are $$=$1 */
  		;
  
+ /*
+  * The precedence declaration for the opt_analyze EMPTY case, below, is
+  * necessary to prevent a shift/reduce conflict in the second production for
+  * ExplainStmt, above.  Otherwise, when the parser encounters "EXPLAIN (", it
+  * can't tell whether the "(" is the beginning of a SelectStmt or the beginning
+  * of the options list.  The precedence declaration below forces the latter
+  * interpretation.
+  *
+  * It might seem that we could get away with simply changing the definition of
+  * ExplainableStmt to use select_without_parens rather than SelectStmt, but
+  * that does not work, because select_without_parens produces expressions such
+  * as "(SELECT NULL) ORDER BY 1" that we interpret as legal queries.
+  */
  opt_analyze:
  			analyze_keyword			{ $$ = TRUE; }
! 			| /* EMPTY */			%prec UMINUS { $$ = FALSE; }	
  		;
  
  /*****************************************************************************
*** a/src/include/nodes/makefuncs.h
--- b/src/include/nodes/makefuncs.h
***************
*** 69,72 **** extern DefElem *makeDefElem(char *name, Node *arg);
--- 69,74 ----
  extern DefElem *makeDefElemExtended(char *namespace, char *name, Node *arg,
  									DefElemAction defaction);
  
+ extern ExplainStmt *makeExplain(List *options, Node *query);
+ 
  #endif   /* MAKEFUNC_H */