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Go back to using a separate method for doing ILIKE for single byte

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character encodings that doesn't involve calling lower(). This should
cure the performance regression in this case complained of by Guillaume
Smet. It still leaves the horrid performance for multi-byte encodings
introduced in 8.2, but there's no obvious solution for that in sight.
This commit is contained in:
Andrew Dunstan
2007-09-22 03:58:34 +00:00
parent b5d1608b0a
commit e152893305
2 changed files with 55 additions and 17 deletions
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45
src/backend/utils/adt/like.c
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@ -11,7 +11,7 @@
* Portions Copyright (c) 1994, Regents of the University of California
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/utils/adt/like.c,v 1.70 2007/09/21 22:52:52 tgl Exp $
* $PostgreSQL: pgsql/src/backend/utils/adt/like.c,v 1.71 2007/09/22 03:58:34 adunstan Exp $
*
*-------------------------------------------------------------------------
*/
@ -36,6 +36,8 @@ static text *MB_do_like_escape(text *, text *);
static int UTF8_MatchText(char *t, int tlen, char *p, int plen);
static int SB_IMatchText(char *t, int tlen, char *p, int plen);
static int GenericMatchText(char *s, int slen, char* p, int plen);
static int Generic_Text_IC_like(text *str, text *pat);
@ -104,6 +106,12 @@ wchareq(char *p1, char *p2)
#include "like_match.c"
/* setup to compile like_match.c for single byte case insensitive matches */
#define MATCH_LOWER
#define NextChar(p, plen) NextByte((p), (plen))
#define MatchText SB_IMatchText
#include "like_match.c"
/* setup to compile like_match.c for UTF8 encoding, using fast NextChar */
@ -132,16 +140,33 @@ Generic_Text_IC_like(text *str, text *pat)
int slen,
plen;
/* Force inputs to lower case to achieve case insensitivity */
str = DatumGetTextP(DirectFunctionCall1(lower, PointerGetDatum(str)));
pat = DatumGetTextP(DirectFunctionCall1(lower, PointerGetDatum(pat)));
/* lower's result is never packed, so OK to use old macros here */
s = VARDATA(str);
slen = (VARSIZE(str) - VARHDRSZ);
p = VARDATA(pat);
plen = (VARSIZE(pat) - VARHDRSZ);
/* For efficiency reasons, in the single byte case we don't call
* lower() on the pattern and text, but instead call to_lower on each
* character. In the multi-byte case we don't have much choice :-(
*/
return GenericMatchText(s, slen, p, plen);
if (pg_database_encoding_max_length() > 1)
{
/* lower's result is never packed, so OK to use old macros here */
pat = DatumGetTextP(DirectFunctionCall1(lower, PointerGetDatum(pat)));
p = VARDATA(pat);
plen = (VARSIZE(pat) - VARHDRSZ);
str = DatumGetTextP(DirectFunctionCall1(lower, PointerGetDatum(str)));
s = VARDATA(str);
slen = (VARSIZE(str) - VARHDRSZ);
if (GetDatabaseEncoding() == PG_UTF8)
return UTF8_MatchText(s, slen, p, plen);
else
return MB_MatchText(s, slen, p, plen);
}
else
{
p = VARDATA_ANY(pat);
plen = VARSIZE_ANY_EXHDR(pat);
s = VARDATA_ANY(str);
slen = VARSIZE_ANY_EXHDR(str);
return SB_IMatchText(s, slen, p, plen);
}
}
/*