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| author | Tom Lane <tgl@sss.pgh.pa.us> | 2005-11-18 23:08:13 +0000 |
|---|---|---|
| committer | Tom Lane <tgl@sss.pgh.pa.us> | 2005-11-18 23:08:13 +0000 |
| commit | dccfa4d3f2f9716632ad946a1582bff3be9e70f0 (patch) | |
| tree | 7c2f97848d5cc0a2d1150c9014f76232a6ab6ec5 | |
| parent | 1012a93264b1a5bc51b4bcd622c0149dc47e974b (diff) | |
| download | postgresql-dccfa4d3f2f9716632ad946a1582bff3be9e70f0.tar.gz postgresql-dccfa4d3f2f9716632ad946a1582bff3be9e70f0.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.
| -rw-r--r-- | src/backend/parser/parse_expr.c | 14 |
1 files changed, 11 insertions, 3 deletions
diff --git a/src/backend/parser/parse_expr.c b/src/backend/parser/parse_expr.c index ab9279abd30..9146887adc3 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 1.185 2005/10/15 02:49:22 momjian Exp $ + * $PostgreSQL: pgsql/src/backend/parser/parse_expr.c,v 1.185.2.1 2005/11/18 23:08:13 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -1664,8 +1664,12 @@ 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); @@ -1688,8 +1692,12 @@ exprTypmod(Node *expr) int32 typmod; ListCell *arg; + if (exprType((Node *) linitial(mexpr->args)) != minmaxtype) + return -1; typmod = exprTypmod((Node *) linitial(mexpr->args)); - foreach(arg, mexpr->args) + if (typmod < 0) + return -1; /* no point in trying harder */ + for_each_cell(arg, lnext(list_head(mexpr->args))) { Node *e = (Node *) lfirst(arg); |