queryid-zero.patch

diff --git a/contrib/pg_stat_statements/pg_stat_statements.c b/contrib/pg_stat_statements/pg_stat_statements.c
index 137b242..bebfff1 100644
*** a/contrib/pg_stat_statements/pg_stat_statements.c
--- b/contrib/pg_stat_statements/pg_stat_statements.c
*************** pgss_post_parse_analyze(ParseState *psta
*** 602,610 ****
  	if (!pgss || !pgss_hash)
  		return;
  
! 	/* We do nothing with utility statements at this stage */
  	if (query->utilityStmt)
  		return;
  
  	/* Set up workspace for query jumbling */
  	jstate.jumble = (unsigned char *) palloc(JUMBLE_SIZE);
--- 602,620 ----
  	if (!pgss || !pgss_hash)
  		return;
  
! 	/*
! 	 * Utility statements get queryId zero.  We do this even in cases where
! 	 * the statement contains an optimizable statement for which a queryId
! 	 * could be derived (such as EXPLAIN or DECLARE CURSOR).  For such cases,
! 	 * runtime control will first go through ProcessUtility and then the
! 	 * executor, and we don't want the executor hooks to do anything, since
! 	 * we are already measuring the statement's costs at the utility level.
! 	 */
  	if (query->utilityStmt)
+ 	{
+ 		query->queryId = 0;
  		return;
+ 	}
  
  	/* Set up workspace for query jumbling */
  	jstate.jumble = (unsigned char *) palloc(JUMBLE_SIZE);
*************** pgss_post_parse_analyze(ParseState *psta
*** 619,624 ****
--- 629,641 ----
  	query->queryId = hash_any(jstate.jumble, jstate.jumble_len);
  
  	/*
+ 	 * If we are unlucky enough to get a hash of zero, use 1 instead, to
+ 	 * prevent confusion with the utility-statement case.
+ 	 */
+ 	if (query->queryId == 0)
+ 		query->queryId = 1;
+ 
+ 	/*
  	 * If we were able to identify any ignorable constants, we immediately
  	 * create a hash table entry for the query, so that we can record the
  	 * normalized form of the query string.  If there were no such constants,
*************** pgss_ExecutorStart(QueryDesc *queryDesc,
*** 649,655 ****
  	else
  		standard_ExecutorStart(queryDesc, eflags);
  
! 	if (pgss_enabled())
  	{
  		/*
  		 * Set up to track total elapsed time in ExecutorRun.  Make sure the
--- 666,677 ----
  	else
  		standard_ExecutorStart(queryDesc, eflags);
  
! 	/*
! 	 * If query has queryId zero, don't track it.  This prevents double
! 	 * counting of optimizable statements that are directly contained in
! 	 * utility statements.
! 	 */
! 	if (pgss_enabled() && queryDesc->plannedstmt->queryId != 0)
  	{
  		/*
  		 * Set up to track total elapsed time in ExecutorRun.  Make sure the
*************** pgss_ExecutorFinish(QueryDesc *queryDesc
*** 719,731 ****
  static void
  pgss_ExecutorEnd(QueryDesc *queryDesc)
  {
! 	if (queryDesc->totaltime && pgss_enabled())
! 	{
! 		uint32		queryId;
! 
! 		/* Query's ID should have been filled in by post-analyze hook */
! 		queryId = queryDesc->plannedstmt->queryId;
  
  		/*
  		 * Make sure stats accumulation is done.  (Note: it's okay if several
  		 * levels of hook all do this.)
--- 741,750 ----
  static void
  pgss_ExecutorEnd(QueryDesc *queryDesc)
  {
! 	uint32		queryId = queryDesc->plannedstmt->queryId;
  
+ 	if (queryId != 0 && queryDesc->totaltime && pgss_enabled())
+ 	{
  		/*
  		 * Make sure stats accumulation is done.  (Note: it's okay if several
  		 * levels of hook all do this.)