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| author | Tom Lane <tgl@sss.pgh.pa.us> | 2005-11-18 23:08:00 +0000 |
|---|---|---|
| committer | Tom Lane <tgl@sss.pgh.pa.us> | 2005-11-18 23:08:00 +0000 |
| commit | 8685c472235b7a5bcc786f66ba9adde44e3d670c (patch) | |
| tree | 83d8ef43a21d919000cf20f161907dff2cb4a144 | |
| parent | b410475672eaf06ba91a03c50c571bd52fd81a32 (diff) | |
| download | postgresql-8685c472235b7a5bcc786f66ba9adde44e3d670c.tar.gz postgresql-8685c472235b7a5bcc786f66ba9adde44e3d670c.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..3a57e5b5147 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 1.186 2005/11/18 23:08:00 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); |