From: drh <drh@noemail.net>
Date: Wed, 27 Mar 2013 15:04:28 +0000 (+0000)
Subject: A fix an test-case for the ORDER BY problem identified by ticket [a179fe7465].
X-Git-Tag: version-3.7.16.1~4^2~2
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=8a1b87cb971a52b9d782def9b70827d9fc302a3f;p=thirdparty%2Fsqlite.git

A fix an test-case for the ORDER BY problem identified by ticket [a179fe7465].
This change causes sorting to occur in some cases where it is not strictly
necessary.  Further work is needed to avoid those extra sorts.

FossilOrigin-Name: 488089e615e375c01b31544f06e801af950ae3db
---

diff --git a/manifest b/manifest
index 007356f176..391a2dd073 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Candidate\sfix\sfor\sticket\s[6bfb98dfc0c]:\sMake\ssure\sinvalid\scursors\sdrop\sall\nreferences\sto\sdatabase\spages\sprior\sto\sdoing\sany\sinsert\sor\supdate.
-D 2013-03-27T03:15:23.329
+C A\sfix\san\stest-case\sfor\sthe\sORDER\sBY\sproblem\sidentified\sby\sticket\s[a179fe7465].\nThis\schange\scauses\ssorting\sto\soccur\sin\ssome\scases\swhere\sit\sis\snot\sstrictly\nnecessary.\s\sFurther\swork\sis\sneeded\sto\savoid\sthose\sextra\ssorts.
+D 2013-03-27T15:04:28.049
 F Makefile.arm-wince-mingw32ce-gcc d6df77f1f48d690bd73162294bbba7f59507c72f
 F Makefile.in df3e48659d80e1b7765785d8d66c86b320f72cc7
 F Makefile.linux-gcc 91d710bdc4998cb015f39edf3cb314ec4f4d7e23
@@ -252,7 +252,7 @@ F src/vtab.c b05e5f1f4902461ba9f5fc49bb7eb7c3a0741a83
 F src/wal.c f5c7b5027d0ed0e9bc9afeb4a3a8dfea762ec7d2
 F src/wal.h 29c197540b19044e6cd73487017e5e47a1d3dac6
 F src/walker.c 3d75ba73de15e0f8cd0737643badbeb0e002f07b
-F src/where.c 9a16c0b84bbeb054d11fda96e9e037ae310bd54e
+F src/where.c 979868386da8fa8e50d74bde97216849add43db2
 F test/8_3_names.test 631ea964a3edb091cf73c3b540f6bcfdb36ce823
 F test/aggerror.test a867e273ef9e3d7919f03ef4f0e8c0d2767944f2
 F test/aggnested.test 45c0201e28045ad38a530b5a144b73cd4aa2cfd6
@@ -646,6 +646,7 @@ F test/openv2.test 0d3040974bf402e19b7df4b783e447289d7ab394
 F test/orderby1.test f33968647da5c546528fe4d2bf86c6a6a2e5a7ae
 F test/orderby2.test bc11009f7cd99d96b1b11e57b199b00633eb5b04
 F test/orderby3.test 8619d06a3debdcd80a27c0fdea5c40b468854b99
+F test/orderby4.test 4d39bfbaaa3ae64d026ca2ff166353d2edca4ba4
 F test/oserror.test 50417780d0e0d7cd23cf12a8277bb44024765df3
 F test/pager1.test 31c04bec797dda1bde337810b52efa08d1f1f08e
 F test/pager2.test 745b911dde3d1f24ae0870bd433dfa83d7c658c1
@@ -1040,7 +1041,10 @@ F tool/vdbe-compress.tcl f12c884766bd14277f4fcedcae07078011717381
 F tool/warnings-clang.sh f6aa929dc20ef1f856af04a730772f59283631d4
 F tool/warnings.sh fbc018d67fd7395f440c28f33ef0f94420226381
 F tool/win/sqlite.vsix 97894c2790eda7b5bce3cc79cb2a8ec2fde9b3ac
-P 5062db672c00c3365d51cd6b39815078f5b6b525
-R 444ec66222f6e3876b5a1bc78bf6602c
+P 322a5f086d9ee46017f750df81527799a54ae258
+R b585a02d8fa68b00b6cca0df4ff7837d
+T *branch * orderby-fix
+T *sym-orderby-fix *
+T -sym-trunk *
 U drh
-Z 3d135e15ecdab16eb6decd45c9d13940
+Z 030131c01bf39bf419a41cdbf4bff578
diff --git a/manifest.uuid b/manifest.uuid
index ed40effb49..22f49c1cad 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-322a5f086d9ee46017f750df81527799a54ae258
\ No newline at end of file
+488089e615e375c01b31544f06e801af950ae3db
\ No newline at end of file
diff --git a/src/where.c b/src/where.c
index 9b64fd72fe..323b568c83 100644
--- a/src/where.c
+++ b/src/where.c
@@ -262,6 +262,8 @@ struct WhereCost {
 #define WHERE_REVERSE      0x01000000  /* Scan in reverse order */
 #define WHERE_UNIQUE       0x02000000  /* Selects no more than one row */
 #define WHERE_ALL_UNIQUE   0x04000000  /* This and all prior have one row */
+#define WHERE_OB_UNIQUE    0x00004000  /* Values in ORDER BY columns are 
+                                       ** different for every output row */
 #define WHERE_VIRTUALTABLE 0x08000000  /* Use virtual-table processing */
 #define WHERE_MULTI_OR     0x10000000  /* OR using multiple indices */
 #define WHERE_TEMP_INDEX   0x20000000  /* Uses an ephemeral index */
@@ -2903,7 +2905,8 @@ static int isSortingIndex(
   WhereBestIdx *p,    /* Best index search context */
   Index *pIdx,        /* The index we are testing */
   int base,           /* Cursor number for the table to be sorted */
-  int *pbRev          /* Set to 1 for reverse-order scan of pIdx */
+  int *pbRev,         /* Set to 1 for reverse-order scan of pIdx */
+  int *pbObUnique     /* ORDER BY column values will different in every row */
 ){
   int i;                        /* Number of pIdx terms used */
   int j;                        /* Number of ORDER BY terms satisfied */
@@ -2917,9 +2920,12 @@ static int isSortingIndex(
   int nPriorSat;                /* ORDER BY terms satisfied by outer loops */
   int seenRowid = 0;            /* True if an ORDER BY rowid term is seen */
   int uniqueNotNull;            /* pIdx is UNIQUE with all terms are NOT NULL */
+  int outerObUnique;            /* Outer loops generate different values in
+                                ** every row for the ORDER BY columns */
 
   if( p->i==0 ){
     nPriorSat = 0;
+    outerObUnique = 1;
   }else{
     nPriorSat = p->aLevel[p->i-1].plan.nOBSat;
     if( (p->aLevel[p->i-1].plan.wsFlags & WHERE_ORDERED)==0 ){
@@ -2932,6 +2938,7 @@ static int isSortingIndex(
       ** optimization is disabled */
       return nPriorSat;
     }
+    outerObUnique = (p->aLevel[p->i-1].plan.wsFlags & WHERE_OB_UNIQUE)!=0;
   }
   pOrderBy = p->pOrderBy;
   assert( pOrderBy!=0 );
@@ -3073,11 +3080,20 @@ static int isSortingIndex(
       uniqueNotNull = 0;
     }
   }
+  if( seenRowid ){
+    uniqueNotNull = 1;
+  }else if( uniqueNotNull==0 || i<pIdx->nColumn ){
+    uniqueNotNull = 0;
+  }
 
   /* If we have not found at least one ORDER BY term that matches the
   ** index, then show no progress. */
   if( pOBItem==&pOrderBy->a[nPriorSat] ) return nPriorSat;
 
+  /* */  
+  if( outerObUnique==0 && uniqueNotNull==0 ) return nPriorSat;
+  *pbObUnique = uniqueNotNull;
+
   /* Return the necessary scan order back to the caller */
   *pbRev = sortOrder & 1;
 
@@ -3085,7 +3101,7 @@ static int isSortingIndex(
   ** possible for a single row from this table to match, then skip over
   ** any additional ORDER BY terms dealing with this table.
   */
-  if( seenRowid || (uniqueNotNull && i>=pIdx->nColumn) ){
+  if( uniqueNotNull ){
     /* Advance j over additional ORDER BY terms associated with base */
     WhereMaskSet *pMS = p->pWC->pMaskSet;
     Bitmask m = ~getMask(pMS, base);
@@ -3369,12 +3385,14 @@ static void bestBtreeIndex(WhereBestIdx *p){
     ** variable.  */
     if( bSort && (pSrc->jointype & JT_LEFT)==0 ){
       int bRev = 2;
-      WHERETRACE(("      --> before isSortingIndex: nPriorSat=%d\n",nPriorSat));
-      pc.plan.nOBSat = isSortingIndex(p, pProbe, iCur, &bRev);
-      WHERETRACE(("      --> after  isSortingIndex: bRev=%d nOBSat=%d\n",
-                  bRev, pc.plan.nOBSat));
+      int bObUnique = 0;
+      WHERETRACE(("      --> before isSortIndex: nPriorSat=%d\n",nPriorSat));
+      pc.plan.nOBSat = isSortingIndex(p, pProbe, iCur, &bRev, &bObUnique);
+      WHERETRACE(("      --> after  isSortIndex: bRev=%d bObU=%d nOBSat=%d\n",
+                  bRev, bObUnique, pc.plan.nOBSat));
       if( nPriorSat<pc.plan.nOBSat || (pc.plan.wsFlags & WHERE_ALL_UNIQUE)!=0 ){
         pc.plan.wsFlags |= WHERE_ORDERED;
+        if( bObUnique ) pc.plan.wsFlags |= WHERE_OB_UNIQUE;
       }
       if( nOrderBy==pc.plan.nOBSat ){
         bSort = 0;
diff --git a/test/orderby4.test b/test/orderby4.test
new file mode 100644
index 0000000000..ec6eb041f6
--- /dev/null
+++ b/test/orderby4.test
@@ -0,0 +1,56 @@
+# 2013 March 26
+#
+# The author disclaims copyright to this source code.  In place of
+# a legal notice, here is a blessing:
+#
+#    May you do good and not evil.
+#    May you find forgiveness for yourself and forgive others.
+#    May you share freely, never taking more than you give.
+#
+#***********************************************************************
+# This file implements regression tests for SQLite library.  The
+# focus of this file is testing that the optimizations that disable
+# ORDER BY clauses work correctly on multi-value primary keys and
+# unique indices when only some prefix of the terms in the key are
+# used.  See ticket http://www.sqlite.org/src/info/a179fe74659
+#
+
+
+set testdir [file dirname $argv0]
+source $testdir/tester.tcl
+set ::testprefix orderby4
+
+# Generate test data for a join.  Verify that the join gets the
+# correct answer.
+#
+do_execsql_test 1.1 {
+  CREATE TABLE t1(a, b, PRIMARY KEY(a,b));
+  INSERT INTO t1 VALUES(1,1),(1,2);
+  CREATE TABLE t2(x, y, PRIMARY KEY(x,y));
+  INSERT INTO t2 VALUES(3,3),(4,4);
+  SELECT a, x FROM t1, t2 ORDER BY 1, 2;
+} {1 3 1 3 1 4 1 4}
+do_execsql_test 1.2 {
+  SELECT a, x FROM t1 CROSS JOIN t2 ORDER BY 1, 2;
+} {1 3 1 3 1 4 1 4}
+do_execsql_test 1.3 {
+  SELECT a, x FROM t2 CROSS JOIN t1 ORDER BY 1, 2;
+} {1 3 1 3 1 4 1 4}
+
+do_execsql_test 2.1 {
+  CREATE TABLE t3(a);
+  INSERT INTO t3 VALUES(1),(1);
+  CREATE INDEX t3a ON t3(a);
+  CREATE TABLE t4(x);
+  INSERT INTO t4 VALUES(3),(4);
+  CREATE INDEX t4x ON t4(x);
+  SELECT a, x FROM t3, t4 ORDER BY 1, 2;
+} {1 3 1 3 1 4 1 4}
+do_execsql_test 2.2 {
+  SELECT a, x FROM t3 CROSS JOIN t4 ORDER BY 1, 2;
+} {1 3 1 3 1 4 1 4}
+do_execsql_test 2.3 {
+  SELECT a, x FROM t4 CROSS JOIN t3 ORDER BY 1, 2;
+} {1 3 1 3 1 4 1 4}
+
+finish_test