From 9fc24f2bf6e549cab53c462adb9100cb5ad8bf2b Mon Sep 17 00:00:00 2001 From: Tom Lane Date: Fri, 21 Oct 2005 16:43:33 +0000 Subject: Fix EXPLAIN ANALYZE bug noted by Wiebe Cazemier: although we were properly advancing the CommandCounter between multiple sub-queries generated by rules, we forgot to update the snapshot being used, so that the successive sub-queries didn't actually see each others' results. This is still not *exactly* like the semantics of normal execution of the same queries, in that we don't take new transaction snapshots and hence don't see changes from concurrently committed commands, but I think that's OK and probably even preferable for EXPLAIN ANALYZE. --- src/backend/commands/explain.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) (limited to 'src/backend/commands/explain.c') diff --git a/src/backend/commands/explain.c b/src/backend/commands/explain.c index d470990e942..08480631fec 100644 --- a/src/backend/commands/explain.c +++ b/src/backend/commands/explain.c @@ -7,7 +7,7 @@ * Portions Copyright (c) 1994-5, Regents of the University of California * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/commands/explain.c,v 1.138 2005/10/15 02:49:15 momjian Exp $ + * $PostgreSQL: pgsql/src/backend/commands/explain.c,v 1.139 2005/10/21 16:43:33 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -196,6 +196,15 @@ ExplainOneQuery(Query *query, ExplainStmt *stmt, TupOutputState *tstate) /* plan the query */ plan = planner(query, isCursor, cursorOptions, NULL); + /* + * Update snapshot command ID to ensure this query sees results of any + * previously executed queries. (It's a bit cheesy to modify + * ActiveSnapshot without making a copy, but for the limited ways in + * which EXPLAIN can be invoked, I think it's OK, because the active + * snapshot shouldn't be shared with anything else anyway.) + */ + ActiveSnapshot->curcid = GetCurrentCommandId(); + /* Create a QueryDesc requesting no output */ queryDesc = CreateQueryDesc(query, plan, ActiveSnapshot, InvalidSnapshot, -- cgit v1.2.3