From: dan <dan@noemail.net>
Date: Wed, 3 Aug 2016 18:00:49 +0000 (+0000)
Subject: Fix a problem with estimating the number of rows visited by a query that uses a multi... 
X-Git-Tag: version-3.15.0~110^2~84
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=3d1fb1dd758781bd6bcffbdb0f3738a7e1c0d2cf;p=thirdparty%2Fsqlite.git

Fix a problem with estimating the number of rows visited by a query that uses a multi-column IN(SELECT...) constraint.

FossilOrigin-Name: 3c2f908f5b7312570cfa74afcf4252a857cb5237
---

diff --git a/manifest b/manifest
index bd4c8f2896..bcec45f458 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Fix\sanother\sproblem\sinvolving\svector\srange\sconstraints\sand\smixed\sASC/DESC\sindexes.
-D 2016-08-03T16:39:04.109
+C Fix\sa\sproblem\swith\sestimating\sthe\snumber\sof\srows\svisited\sby\sa\squery\sthat\suses\sa\smulti-column\sIN(SELECT...)\sconstraint.
+D 2016-08-03T18:00:49.612
 F Makefile.in 6c20d44f72d4564f11652b26291a214c8367e5db
 F Makefile.linux-gcc 7bc79876b875010e8c8f9502eb935ca92aa3c434
 F Makefile.msc 3340e479e5221f06c3d61726f8f7efff885e4233
@@ -463,7 +463,7 @@ F src/vxworks.h d2988f4e5a61a4dfe82c6524dd3d6e4f2ce3cdb9
 F src/wal.c 02eeecc265f6ffd0597378f5d8ae9070b62a406a
 F src/wal.h 6dd221ed384afdc204bc61e25c23ef7fd5a511f2
 F src/walker.c 0f142b5bd3ed2041fc52d773880748b212e63354
-F src/where.c 8bd54861755e2ca54bc36b0dbc655834f363c5ec
+F src/where.c 0a0b8af3920f88467d93019acdf570c4f4192f26
 F src/whereInt.h 14dd243e13b81cbb0a66063d38b70f93a7d6e613
 F src/wherecode.c c2392fa30bcb0c555a8ae402d646b357ca428ad6
 F src/whereexpr.c 4a8cefc7c122132ac9f3ed125c61629a0e3de094
@@ -1021,7 +1021,7 @@ F test/rowid.test 5b7509f384f4f6fae1af3c8c104c8ca299fea18d
 F test/rowvalue.test 56b34d31d91340a6e922e753b798880170cc1aa7
 F test/rowvalue2.test 8d5dfe75b8f4d1868a2f91f0356f20d36cba64ff
 F test/rowvalue3.test dbe935260851b197dfbbbcb0ac2a15cb5f324fd4
-F test/rowvalue4.test b902e053544469e06148f504962abf9afb28be65
+F test/rowvalue4.test 1f0fa2d6e4485c2c35cdb997ba57f572fd9919e0
 F test/rowvaluefault.test 7b16485e3f2b371f3e3d05455b8ded6d0c090244
 F test/rtree.test 0c8d9dd458d6824e59683c19ab2ffa9ef946f798
 F test/run-wordcount.sh 891e89c4c2d16e629cd45951d4ed899ad12afc09
@@ -1514,7 +1514,7 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P 18af74abc8ceae47ab9fbee3e3e5bb37db8fcba5
-R 411ee4bf09cf9ee92d07e741a8c6b68c
+P 1559f4c43473e107f7196eea3ee91c53ede22999
+R f540153e91f079ff5413a490814ad157
 U dan
-Z eb44e2dff5400ed92495955ac9fc17ab
+Z 1ca41c3e8d4f391ec12438826156b785
diff --git a/manifest.uuid b/manifest.uuid
index 97e702c730..d136916990 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-1559f4c43473e107f7196eea3ee91c53ede22999
\ No newline at end of file
+3c2f908f5b7312570cfa74afcf4252a857cb5237
\ No newline at end of file
diff --git a/src/where.c b/src/where.c
index a80054b1c7..877ca72ad1 100644
--- a/src/where.c
+++ b/src/where.c
@@ -2376,14 +2376,23 @@ static int whereLoopAddBtreeIndex(
       pNew->wsFlags |= WHERE_COLUMN_IN;
       if( ExprHasProperty(pExpr, EP_xIsSelect) ){
         /* "x IN (SELECT ...)":  TUNING: the SELECT returns 25 rows */
+        int i;
         nIn = 46;  assert( 46==sqlite3LogEst(25) );
+
+        /* The expression may actually be of the form (x, y) IN (SELECT...).
+        ** In this case there is a separate term for each of (x) and (y).
+        ** However, the nIn multiplier should only be applied once, not once
+        ** for each such term. The following loop checks that pTerm is the
+        ** first such term in use, and sets nIn back to 0 if it is not. */
+        for(i=0; i<pNew->nLTerm-1; i++){
+          if( pNew->aLTerm[i]->pExpr==pExpr ) nIn = 0;
+        }
       }else if( ALWAYS(pExpr->x.pList && pExpr->x.pList->nExpr) ){
         /* "x IN (value, value, ...)" */
         nIn = sqlite3LogEst(pExpr->x.pList->nExpr);
+        assert( nIn>0 );  /* RHS always has 2 or more terms...  The parser
+                          ** changes "x IN (?)" into "x=?". */
       }
-      assert( nIn>0 );  /* RHS always has 2 or more terms...  The parser
-                        ** changes "x IN (?)" into "x=?". */
-
     }else if( eOp & (WO_EQ|WO_IS) ){
       int iCol = pProbe->aiColumn[saved_nEq];
       pNew->wsFlags |= WHERE_COLUMN_EQ;
diff --git a/test/rowvalue4.test b/test/rowvalue4.test
index d615aa8e2e..a187063081 100644
--- a/test/rowvalue4.test
+++ b/test/rowvalue4.test
@@ -212,5 +212,33 @@ ifcapable stat4 {
   }
 }
 
+#------------------------------------------------------------------------
+
+do_execsql_test 5.0 {
+  CREATE TABLE d1(x, y);
+  CREATE TABLE d2(a, b, c);
+  CREATE INDEX d2ab ON d2(a, b);
+  CREATE INDEX d2c ON d2(c);
+
+  WITH i(i) AS (
+    VALUES(1) UNION ALL SELECT i+1 FROM i WHERE i<1000
+  )
+  INSERT INTO d2 SELECT i/3, i%3, i/3 FROM i;
+  ANALYZE;
+}
+
+do_eqp_test 5.1 {
+  SELECT * FROM d2 WHERE 
+    (a, b) IN (SELECT x, y FROM d1) AND
+    (c) IN (SELECT y FROM d1)
+} {
+  0 0 0 {SEARCH TABLE d2 USING INDEX d2ab (a=? AND b=?)}
+  0 0 0 {EXECUTE LIST SUBQUERY 1} 
+  1 0 0 {SCAN TABLE d1}
+  0 0 0 {EXECUTE LIST SUBQUERY 2} 
+  2 0 0 {SCAN TABLE d1}
+}
+
+
 finish_test