diff options
Diffstat (limited to 'src/backend/commands/explain.c')
| -rw-r--r-- | src/backend/commands/explain.c | 12 |
1 files changed, 11 insertions, 1 deletions
diff --git a/src/backend/commands/explain.c b/src/backend/commands/explain.c index 34f6aa51f78..66e795d422d 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 1.127 2004/09/30 17:42:42 tgl Exp $ + * $PostgreSQL: pgsql/src/backend/commands/explain.c,v 1.128 2004/12/12 20:17:06 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -75,6 +75,16 @@ ExplainQuery(ExplainStmt *stmt, DestReceiver *dest) List *rewritten; ListCell *l; + /* + * Because the planner is not cool about not scribbling on its input, + * we make a preliminary copy of the source querytree. This prevents + * problems in the case that the EXPLAIN is in a portal or plpgsql + * function and is executed repeatedly. (See also the same hack in + * DECLARE CURSOR and PREPARE.) XXX the planner really shouldn't + * modify its input ... FIXME someday. + */ + query = copyObject(query); + /* prepare for projection of tuples */ tstate = begin_tup_output_tupdesc(dest, ExplainResultDesc(stmt)); |