From: drh <drh@noemail.net>
Date: Thu, 16 Jan 2014 15:31:41 +0000 (+0000)
Subject: Always use available indices to optimize LIKE operators even if the pattern
X-Git-Tag: version-3.8.3~46
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=6ade453cd844a1cc65648477557d6cb770b60364;p=thirdparty%2Fsqlite.git

Always use available indices to optimize LIKE operators even if the pattern
of the LIKE operator has a COLLATE modifier.  This fixes an ineffiency that
was introduced into 3.7.15 by check-in [8542e6180d4] on 2012-12-08.

FossilOrigin-Name: 16bd54783a3f5531c55564ddefdada657c078eb0
---

diff --git a/manifest b/manifest
index b7d3993e06..1aa2634f3e 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Fix\sharmless\scompiler\swarning\sin\sLEMON.
-D 2014-01-14T10:17:21.693
+C Always\suse\savailable\sindices\sto\soptimize\sLIKE\soperators\seven\sif\sthe\spattern\nof\sthe\sLIKE\soperator\shas\sa\sCOLLATE\smodifier.\s\sThis\sfixes\san\sineffiency\sthat\nwas\sintroduced\sinto\s3.7.15\sby\scheck-in\s[8542e6180d4]\son\s2012-12-08.
+D 2014-01-16T15:31:41.806
 F Makefile.arm-wince-mingw32ce-gcc d6df77f1f48d690bd73162294bbba7f59507c72f
 F Makefile.in 2ef13430cd359f7b361bb863504e227b25cc7f81
 F Makefile.linux-gcc 91d710bdc4998cb015f39edf3cb314ec4f4d7e23
@@ -293,7 +293,7 @@ F src/vtab.c 21b932841e51ebd7d075e2d0ad1415dce8d2d5fd
 F src/wal.c 7dc3966ef98b74422267e7e6e46e07ff6c6eb1b4
 F src/wal.h df01efe09c5cb8c8e391ff1715cca294f89668a4
 F src/walker.c e9e593d5bb798c3e67fc3893dfe7055c9e7d8d74
-F src/where.c 18f07fd0fd116a5880773c689eb7cd8e60175107
+F src/where.c 81cec50fe73633144b0730de477e141c53485862
 F src/whereInt.h 96a75c61f1d2b9d4a8e4bb17d89deb0cf7cba358
 F test/8_3_names.test ebbb5cd36741350040fd28b432ceadf495be25b2
 F test/aggerror.test a867e273ef9e3d7919f03ef4f0e8c0d2767944f2
@@ -646,7 +646,7 @@ F test/jrnlmode3.test 556b447a05be0e0963f4311e95ab1632b11c9eaa
 F test/keyword1.test a2400977a2e4fde43bf33754c2929fda34dbca05
 F test/lastinsert.test 42e948fd6442f07d60acbd15d33fb86473e0ef63
 F test/laststmtchanges.test ae613f53819206b3222771828d024154d51db200
-F test/like.test 935fb4f608e3ea126891496a6e99b9468372bf5c
+F test/like.test e191e536d0fcd722a6b965e7cd1ee0bfd12a5991
 F test/like2.test 3b2ee13149ba4a8a60b59756f4e5d345573852da
 F test/limit.test cc0ab63385239b63c72452b0e93700bf5e8f0b99
 F test/loadext.test 92e6dfefd1229c3ef4aaabd87419efd8fa57a7a5
@@ -1148,7 +1148,7 @@ F tool/vdbe-compress.tcl 0cf56e9263a152b84da86e75a5c0cdcdb7a47891
 F tool/warnings-clang.sh f6aa929dc20ef1f856af04a730772f59283631d4
 F tool/warnings.sh d1a6de74685f360ab718efda6265994b99bbea01
 F tool/win/sqlite.vsix 030f3eeaf2cb811a3692ab9c14d021a75ce41fff
-P 1e131094b522103a0829f72193b067b04e42ce82
-R fe4a4148cfbc4d588ee2679597656da4
-U mistachkin
-Z d589f5ec7c09b4ac8c97497c20166016
+P f61a70589ac7e05008a362bd9d5b7bde5d07a758
+R c3393c71f3ebd7292d430bc7115b905d
+U drh
+Z 57df34b30b12b159eb99c0c8be54bec6
diff --git a/manifest.uuid b/manifest.uuid
index d14b8afba5..b734040749 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-f61a70589ac7e05008a362bd9d5b7bde5d07a758
\ No newline at end of file
+16bd54783a3f5531c55564ddefdada657c078eb0
\ No newline at end of file
diff --git a/src/where.c b/src/where.c
index d5444a6054..a9f527313a 100644
--- a/src/where.c
+++ b/src/where.c
@@ -667,7 +667,7 @@ static int isLikeOrGlob(
   }
   assert( pLeft->iColumn!=(-1) ); /* Because IPK never has AFF_TEXT */
 
-  pRight = pList->a[0].pExpr;
+  pRight = sqlite3ExprSkipCollate(pList->a[0].pExpr);
   op = pRight->op;
   if( op==TK_VARIABLE ){
     Vdbe *pReprepare = pParse->pReprepare;
diff --git a/test/like.test b/test/like.test
index 230dc74fed..923272cfb2 100644
--- a/test/like.test
+++ b/test/like.test
@@ -893,5 +893,60 @@ do_test like-11.10 {
   }
 } {abc abcd sort {} t11cb}
 
+# A COLLATE clause on the pattern does not change the result of a
+# LIKE operator.
+#
+do_execsql_test like-12.1 {
+  CREATE TABLE t12nc(id INTEGER, x TEXT UNIQUE COLLATE nocase);
+  INSERT INTO t12nc VALUES(1,'abcde'),(2,'uvwxy'),(3,'ABCDEF');
+  CREATE TABLE t12b(id INTEGER, x TEXT UNIQUE COLLATE binary);
+  INSERT INTO t12b VALUES(1,'abcde'),(2,'uvwxy'),(3,'ABCDEF');
+  SELECT id FROM t12nc WHERE x LIKE 'abc%' ORDER BY +id;
+} {1 3}
+do_execsql_test like-12.2 {
+  SELECT id FROM t12b WHERE x LIKE 'abc%' ORDER BY +id;
+} {1 3}
+do_execsql_test like-12.3 {
+  SELECT id FROM t12nc WHERE x LIKE 'abc%' COLLATE binary ORDER BY +id;
+} {1 3}
+do_execsql_test like-12.4 {
+  SELECT id FROM t12b WHERE x LIKE 'abc%' COLLATE binary ORDER BY +id;
+} {1 3}
+do_execsql_test like-12.5 {
+  SELECT id FROM t12nc WHERE x LIKE 'abc%' COLLATE nocase ORDER BY +id;
+} {1 3}
+do_execsql_test like-12.6 {
+  SELECT id FROM t12b WHERE x LIKE 'abc%' COLLATE nocase ORDER BY +id;
+} {1 3}
+
+# Adding a COLLATE clause to the pattern of a LIKE operator does nothing
+# to change the suitability of using an index to satisfy that LIKE
+# operator.
+#
+do_execsql_test like-12.11 {
+  EXPLAIN QUERY PLAN
+  SELECT id FROM t12nc WHERE x LIKE 'abc%' ORDER BY +id;
+} {/SEARCH/}
+do_execsql_test like-12.12 {
+  EXPLAIN QUERY PLAN
+  SELECT id FROM t12b WHERE x LIKE 'abc%' ORDER BY +id;
+} {/SCAN/}
+do_execsql_test like-12.13 {
+  EXPLAIN QUERY PLAN
+  SELECT id FROM t12nc WHERE x LIKE 'abc%' COLLATE nocase ORDER BY +id;
+} {/SEARCH/}
+do_execsql_test like-12.14 {
+  EXPLAIN QUERY PLAN
+  SELECT id FROM t12b WHERE x LIKE 'abc%' COLLATE nocase ORDER BY +id;
+} {/SCAN/}
+do_execsql_test like-12.15 {
+  EXPLAIN QUERY PLAN
+  SELECT id FROM t12nc WHERE x LIKE 'abc%' COLLATE binary ORDER BY +id;
+} {/SEARCH/}
+do_execsql_test like-12.16 {
+  EXPLAIN QUERY PLAN
+  SELECT id FROM t12b WHERE x LIKE 'abc%' COLLATE binary ORDER BY +id;
+} {/SCAN/}
+
 
 finish_test