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| author | Tom Lane <tgl@sss.pgh.pa.us> | 2005-10-21 16:43:33 +0000 |
|---|---|---|
| committer | Tom Lane <tgl@sss.pgh.pa.us> | 2005-10-21 16:43:33 +0000 |
| commit | 9fc24f2bf6e549cab53c462adb9100cb5ad8bf2b (patch) | |
| tree | e5c50d92be819fa9bc0b9b16053f00a6112ad093 /src/backend/commands/explain.c | |
| parent | ef3b7cd3282a50b382b0ae76f8b6fe541d52b857 (diff) | |
| download | postgresql-9fc24f2bf6e549cab53c462adb9100cb5ad8bf2b.tar.gz postgresql-9fc24f2bf6e549cab53c462adb9100cb5ad8bf2b.zip | |
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.
Diffstat (limited to 'src/backend/commands/explain.c')
| -rw-r--r-- | src/backend/commands/explain.c | 11 |
1 files changed, 10 insertions, 1 deletions
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, |