Fix regex_fixed_prefix() to cope reasonably well with regex patterns of the

form '^(foo)$'.  Before, these could never be optimized into indexscans.
The recent changes to make psql and pg_dump generate such patterns (for \d
commands and -t and related switches, respectively) therefore represented
a big performance hit for people with large pg_class catalogs, as seen in
recent gripe from Erik Jones.  While at it, be more paranoid about
case-sensitivity checking in multibyte encodings, and fix some other
corner cases in which a regex might be interpreted too liberally.

1 files changed, 2 insertions, 1 deletions

diff --git a/src/include/utils/builtins.h b/src/include/utils/builtins.h
index e1ed7b862b3..173339683af 100644
--- a/src/include/utils/builtins.h
+++ b/src/include/utils/builtins.h
@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2006, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/utils/builtins.h,v 1.282 2006/09/18 22:40:40 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/utils/builtins.h,v 1.282.2.1 2007/01/03 22:39:35 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -477,6 +477,7 @@ extern Datum textregexsubstr(PG_FUNCTION_ARGS);
 extern Datum textregexreplace_noopt(PG_FUNCTION_ARGS);
 extern Datum textregexreplace(PG_FUNCTION_ARGS);
 extern Datum similar_escape(PG_FUNCTION_ARGS);
+extern bool regex_flavor_is_basic(void);
 
 /* regproc.c */
 extern Datum regprocin(PG_FUNCTION_ARGS);