commit b975d7c2fe1b36a3ded1e0960be191466704e0fc
Author: Satoshi Nagayasu <snaga@uptime.jp>
Date:   Sat Aug 8 08:51:45 2015 +0000

    Fix pg_stat_statements to avoid assert failure when queryId already has non-zero value.

diff --git a/contrib/pg_stat_statements/pg_stat_statements.c b/contrib/pg_stat_statements/pg_stat_statements.c
index 59b8a2e..84c5200 100644
--- a/contrib/pg_stat_statements/pg_stat_statements.c
+++ b/contrib/pg_stat_statements/pg_stat_statements.c
@@ -776,8 +776,9 @@ pgss_post_parse_analyze(ParseState *pstate, Query *query)
 	if (prev_post_parse_analyze_hook)
 		prev_post_parse_analyze_hook(pstate, query);
 
-	/* Assert we didn't do this already */
-	Assert(query->queryId == 0);
+	/* Assume that other module has calculated and set queryId */
+	if (query->queryId > 0)
+		return;
 
 	/* Safety check... */
 	if (!pgss || !pgss_hash)