diff options
Diffstat (limited to 'src/backend/optimizer/plan/planner.c')
| -rw-r--r-- | src/backend/optimizer/plan/planner.c | 23 |
1 files changed, 12 insertions, 11 deletions
diff --git a/src/backend/optimizer/plan/planner.c b/src/backend/optimizer/plan/planner.c index f9c70f7137d..5951e8f0c9b 100644 --- a/src/backend/optimizer/plan/planner.c +++ b/src/backend/optimizer/plan/planner.c @@ -8,7 +8,7 @@ * * * IDENTIFICATION - * $Header: /cvsroot/pgsql/src/backend/optimizer/plan/planner.c,v 1.93 2000/10/26 21:36:09 tgl Exp $ + * $Header: /cvsroot/pgsql/src/backend/optimizer/plan/planner.c,v 1.94 2000/11/05 00:15:53 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -809,25 +809,26 @@ union_planner(Query *parse, if (IsA(parse->limitCount, Const)) { Const *limitc = (Const *) parse->limitCount; - int count = (int) (limitc->constvalue); + int32 count = DatumGetInt32(limitc->constvalue); /* - * The constant can legally be either 0 ("ALL") or a - * positive integer. If it is not ALL, we also need - * to consider the OFFSET part of LIMIT. + * A NULL-constant LIMIT represents "LIMIT ALL", + * which we treat the same as no limit (ie, + * expect to retrieve all the tuples). */ - if (count > 0) + if (!limitc->constisnull && count > 0) { tuple_fraction = (double) count; + /* We must also consider the OFFSET, if present */ if (parse->limitOffset != NULL) { if (IsA(parse->limitOffset, Const)) { - int offset; + int32 offset; limitc = (Const *) parse->limitOffset; - offset = (int) (limitc->constvalue); - if (offset > 0) + offset = DatumGetInt32(limitc->constvalue); + if (!limitc->constisnull && offset > 0) tuple_fraction += (double) offset; } else @@ -850,14 +851,14 @@ union_planner(Query *parse, } /* - * Check for a retrieve-into-portal, ie DECLARE CURSOR. + * If no LIMIT, check for retrieve-into-portal, ie DECLARE CURSOR. * * We have no real idea how many tuples the user will ultimately * FETCH from a cursor, but it seems a good bet that he * doesn't want 'em all. Optimize for 10% retrieval (you * gotta better number?) */ - if (parse->isPortal) + else if (parse->isPortal) tuple_fraction = 0.10; } |