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| author | Tom Lane <tgl@sss.pgh.pa.us> | 2005-11-18 23:08:28 +0000 |
|---|---|---|
| committer | Tom Lane <tgl@sss.pgh.pa.us> | 2005-11-18 23:08:28 +0000 |
| commit | acd3a4f3c5cce6697f0b152438b7a25288a6aff7 (patch) | |
| tree | 7c81e3d3d77c0f3b8a99c59276adec518b2fe536 /src/backend/parser/parse_expr.c | |
| parent | f583cbc8a000f6c5ff5c2aa63e2f4e95ef119f9a (diff) | |
| download | postgresql-acd3a4f3c5cce6697f0b152438b7a25288a6aff7.tar.gz postgresql-acd3a4f3c5cce6697f0b152438b7a25288a6aff7.zip | |
Fix performance issue in exprTypmod(): for a COALESCE expression, it
recursed twice on its first argument, leading to exponential time spent
on a deep nest of COALESCEs ... such as a deeply nested FULL JOIN would
produce. Per report from Matt Carter.
Diffstat (limited to 'src/backend/parser/parse_expr.c')
| -rw-r--r-- | src/backend/parser/parse_expr.c | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/src/backend/parser/parse_expr.c b/src/backend/parser/parse_expr.c index 9082efe7eaf..f95e58593a4 100644 --- a/src/backend/parser/parse_expr.c +++ b/src/backend/parser/parse_expr.c @@ -8,7 +8,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/parser/parse_expr.c,v 1.179.4.2 2005/05/25 02:17:55 ishii Exp $ + * $PostgreSQL: pgsql/src/backend/parser/parse_expr.c,v 1.179.4.3 2005/11/18 23:08:28 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -1562,8 +1562,12 @@ exprTypmod(Node *expr) int32 typmod; ListCell *arg; + if (exprType((Node *) linitial(cexpr->args)) != coalescetype) + return -1; typmod = exprTypmod((Node *) linitial(cexpr->args)); - foreach(arg, cexpr->args) + if (typmod < 0) + return -1; /* no point in trying harder */ + for_each_cell(arg, lnext(list_head(cexpr->args))) { Node *e = (Node *) lfirst(arg); |