Index: src/backend/utils/adt/like.c
===================================================================
RCS file: /cvsroot/pgsql/src/backend/utils/adt/like.c,v
retrieving revision 1.71
diff -c -r1.71 like.c
*** src/backend/utils/adt/like.c	22 Sep 2007 03:58:34 -0000	1.71
--- src/backend/utils/adt/like.c	22 Sep 2007 12:16:23 -0000
***************
*** 139,144 ****
--- 139,149 ----
  			   *p;
  	int			slen,
  				plen;
+ 	static char patcache[512], lpatcache[512];
+     static int  patcachelen = 0, lpatcachelen = 0;
+ 
+ 	p = VARDATA_ANY(pat);
+ 	plen = VARSIZE_ANY_EXHDR(pat);
  
  	/* 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
***************
*** 147,156 ****
  
  	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);
--- 152,192 ----
  
  	if (pg_database_encoding_max_length() > 1)
  	{
+ 		if (plen > 0  && plen == patcachelen && strncmp(p,patcache,plen) == 0)
+ 		{
+ 			p = lpatcache;
+ 			plen = lpatcachelen;
+ 		}
+ 		else
+ 		{
+ 			char *lp;
+ 			int   lplen;
+ 
+ 			pat = DatumGetTextP(DirectFunctionCall1(lower, 
+ 													PointerGetDatum(pat)));
+ 
+ 			/* lower's result is never packed, so OK to use old macros here */
+ 			lp = VARDATA(pat);
+ 			lplen = (VARSIZE(pat) - VARHDRSZ);
+ 
+ 			if (plen < 512 && lplen < 512)
+ 			{
+ 				patcachelen = plen;
+ 				lpatcachelen = lplen;
+ 				memcpy(patcache,p,plen);
+ 				memcpy(lpatcache,lp,lplen);
+ 			}
+ 			else
+ 			{
+ 				patcachelen = 0;
+ 				lpatcachelen = 0;
+ 			}
+ 
+ 			p = lp;
+ 			plen = lplen;
+ 		}
+ 
  		/* lower's result is never packed, so OK to use old macros here */
  		str = DatumGetTextP(DirectFunctionCall1(lower, PointerGetDatum(str)));
  		s = VARDATA(str);
  		slen = (VARSIZE(str) - VARHDRSZ);
***************
*** 161,168 ****
  	}
  	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);
--- 197,202 ----