diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/backend/commands/explain.c | 12 | ||||
| -rw-r--r-- | src/backend/commands/prepare.c | 15 |
2 files changed, 24 insertions, 3 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)); diff --git a/src/backend/commands/prepare.c b/src/backend/commands/prepare.c index ae9366c5ee1..66fa15c37a3 100644 --- a/src/backend/commands/prepare.c +++ b/src/backend/commands/prepare.c @@ -10,7 +10,7 @@ * Copyright (c) 2002-2004, PostgreSQL Global Development Group * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/commands/prepare.c,v 1.34 2004/12/03 21:26:31 tgl Exp $ + * $PostgreSQL: pgsql/src/backend/commands/prepare.c,v 1.35 2004/12/12 20:17:06 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -48,6 +48,7 @@ void PrepareQuery(PrepareStmt *stmt) { const char *commandTag; + Query *query; List *query_list, *plan_list; @@ -87,8 +88,18 @@ PrepareQuery(PrepareStmt *stmt) * the query. */ + /* + * 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 PREPARE is in a portal or plpgsql + * function and is executed repeatedly. (See also the same hack in + * DECLARE CURSOR and EXPLAIN.) XXX the planner really shouldn't + * modify its input ... FIXME someday. + */ + query = copyObject(stmt->query); + /* Rewrite the query. The result could be 0, 1, or many queries. */ - query_list = QueryRewrite(stmt->query); + query_list = QueryRewrite(query); /* Generate plans for queries. Snapshot is already set. */ plan_list = pg_plan_queries(query_list, NULL, false); |