From: dan <dan@noemail.net>
Date: Fri, 8 Jul 2011 16:10:54 +0000 (+0000)
Subject: Fix for [54844eea3f]: Do not create automatic indexes on correlated sub-queries.
X-Git-Tag: version-3.7.8~38^2~22
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=da79cf0cc9cc00588782f771b76b087460507586;p=thirdparty%2Fsqlite.git

Fix for [54844eea3f]: Do not create automatic indexes on correlated sub-queries.

FossilOrigin-Name: 9f14fa56ba31afe3de8b0cf26ed09573a2cc2283
---

diff --git a/manifest b/manifest
index 9f98ca8728..7bc4892cad 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Extend\sthe\sSQLITE_TESTCTRL_OPTIMIZATIONS\soption\sto\sdisable\sDISTINCT\noptimizations.
-D 2011-07-08T13:07:02.960
+C Fix\sfor\s[54844eea3f]:\sDo\snot\screate\sautomatic\sindexes\son\scorrelated\ssub-queries.
+D 2011-07-08T16:10:54.482
 F Makefile.arm-wince-mingw32ce-gcc d6df77f1f48d690bd73162294bbba7f59507c72f
 F Makefile.in c1d7a7f4fd8da6b1815032efca950e3d5125407e
 F Makefile.linux-gcc 91d710bdc4998cb015f39edf3cb314ec4f4d7e23
@@ -133,7 +133,7 @@ F src/complete.c dc1d136c0feee03c2f7550bafc0d29075e36deac
 F src/ctime.c 7deec4534f3b5a0c3b4a4cbadf809d321f64f9c4
 F src/date.c a3c6842bad7ae632281811de112a8ba63ff08ab3
 F src/delete.c ff68e5ef23aee08c0ff528f699a19397ed8bbed8
-F src/expr.c ab46ab0f0c44979a8164ca31728d7d10ae5e8106
+F src/expr.c 4bbdfaf66bc614be9254ce0c26a17429067a3e07
 F src/fault.c 160a0c015b6c2629d3899ed2daf63d75754a32bb
 F src/fkey.c c8492fed772af1ed61251582707266227612b45b
 F src/func.c 59bb046d7e3df1ab512ac339ccb0a6f996a17cb7
@@ -177,13 +177,13 @@ F src/pragma.c ebcd20f1e654f5cb3aeef864ed69c4697719fbaa
 F src/prepare.c e64261559a3187698a3e7e6c8b001a4f4f98dab4
 F src/printf.c 585a36b6a963df832cfb69505afa3a34ed5ef8a1
 F src/random.c cd4a67b3953b88019f8cd4ccd81394a8ddfaba50
-F src/resolve.c 1c0f32b64f8e3f555fe1f732f9d6f501a7f05706
+F src/resolve.c 36368f44569208fa074e61f4dd0b6c4fb60ca2b4
 F src/rowset.c 69afa95a97c524ba6faf3805e717b5b7ae85a697
 F src/select.c e9d74f943c195f2673990febd3a455b421964ca0
 F src/shell.c 0e0173b3e79d956368013e759f084caa7995ecb1
 F src/sqlite.h.in 4b7255c10d39c5faf089dbd29cde7c367ff39f1f
 F src/sqlite3ext.h 1a1a4f784aa9c3b00edd287940197de52487cd93
-F src/sqliteInt.h a7143a30c5817e5ed6cde42430255face266a710
+F src/sqliteInt.h ba4a6d6288efb25b84bc0d7d0aaf80f9b42523ba
 F src/sqliteLimit.h 164b0e6749d31e0daa1a4589a169d31c0dec7b3d
 F src/status.c 7ac64842c86cec2fc1a1d0e5c16d3beb8ad332bf
 F src/table.c 2cd62736f845d82200acfa1287e33feb3c15d62e
@@ -250,7 +250,7 @@ F src/vtab.c 901791a47318c0562cd0c676a2c6ff1bc530e582
 F src/wal.c 0c70ad7b1cac6005fa5e2cbefd23ee05e391c290
 F src/wal.h 66b40bd91bc29a5be1c88ddd1f5ade8f3f48728a
 F src/walker.c 3112bb3afe1d85dc52317cb1d752055e9a781f8f
-F src/where.c c814c35a2731ff1f636bce7a628be91b0d77d734
+F src/where.c defae982c6a5ced7c9a972a5a4850ad140a6d631
 F test/8_3_names.test b93687beebd17f6ebf812405a6833bae5d1f4199
 F test/aggerror.test a867e273ef9e3d7919f03ef4f0e8c0d2767944f2
 F test/alias.test 4529fbc152f190268a15f9384a5651bbbabc9d87
@@ -718,6 +718,7 @@ F test/tkt-38cb5df375.test 9e9b19857dba0896a8efdaf334d405ba423492f2
 F test/tkt-3998683a16.test 6d1d04d551ed1704eb3396ca87bb9ccc8c5c1eb7
 F test/tkt-3fe897352e.test 10de1a67bd5c66b238a4c96abe55531b37bb4f00
 F test/tkt-4a03edc4c8.test 2865e4edbc075b954daa82f8da7cc973033ec76e
+F test/tkt-54844eea3f.test a12b851128f46a695e4e378cca67409b9b8f5894
 F test/tkt-5d863f876e.test 884072c2de496ddbb90c387c9ebc0d4f44a91b8e
 F test/tkt-5e10420e8d.test 904d1687b3c06d43e5b3555bbcf6802e7c0ffd84
 F test/tkt-5ee23731f.test 3581260f2a71e51db94e1506ba6b0f7311d002a9
@@ -950,7 +951,7 @@ F tool/symbols.sh caaf6ccc7300fd43353318b44524853e222557d5
 F tool/tostr.awk 11760e1b94a5d3dcd42378f3cc18544c06cfa576
 F tool/vdbe-compress.tcl d70ea6d8a19e3571d7ab8c9b75cba86d1173ff0f
 F tool/warnings.sh 2ebae31e1eb352696f3c2f7706a34c084b28c262
-P 71b749a9dca953cdf671d94afec16e2c98f3aee5
-R 26528fdf903671e1d2a91c9d7db991cc
-U drh
-Z 1d6ed3edda2aa263aea05f58878a859f
+P 18501dd1a8aa8299c091c36e35b9a10a29d4467b
+R f7d91718025095a30a469ac579a4e46b
+U dan
+Z fc4423411c04e2aaef6760d45d2bd142
diff --git a/manifest.uuid b/manifest.uuid
index d4fcb0a135..16b8760bdc 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-18501dd1a8aa8299c091c36e35b9a10a29d4467b
\ No newline at end of file
+9f14fa56ba31afe3de8b0cf26ed09573a2cc2283
\ No newline at end of file
diff --git a/src/expr.c b/src/expr.c
index be2f4d7c66..ab4547db9c 100644
--- a/src/expr.c
+++ b/src/expr.c
@@ -902,6 +902,7 @@ SrcList *sqlite3SrcListDup(sqlite3 *db, SrcList *p, int flags){
     pNewItem->jointype = pOldItem->jointype;
     pNewItem->iCursor = pOldItem->iCursor;
     pNewItem->isPopulated = pOldItem->isPopulated;
+    pNewItem->isCorrelated = pOldItem->isCorrelated;
     pNewItem->zIndex = sqlite3DbStrDup(db, pOldItem->zIndex);
     pNewItem->notIndexed = pOldItem->notIndexed;
     pNewItem->pIndex = pOldItem->pIndex;
diff --git a/src/resolve.c b/src/resolve.c
index 74d6aaef93..d29d2a8344 100644
--- a/src/resolve.c
+++ b/src/resolve.c
@@ -996,11 +996,25 @@ static int resolveSelectStep(Walker *pWalker, Select *p){
     for(i=0; i<p->pSrc->nSrc; i++){
       struct SrcList_item *pItem = &p->pSrc->a[i];
       if( pItem->pSelect ){
+        NameContext *pNC;         /* Used to iterate name contexts */
+        int nRef = 0;             /* Refcount for pOuterNC and outer contexts */
         const char *zSavedContext = pParse->zAuthContext;
+
+        /* Count the total number of references to pOuterNC and all of its
+        ** parent contexts. After resolving references to expressions in
+        ** pItem->pSelect, check if this value has changed. If so, then
+        ** SELECT statement pItem->pSelect must be correlated. Set the
+        ** pItem->isCorrelated flag if this is the case. */
+        for(pNC=pOuterNC; pNC; pNC=pNC->pNext) nRef += pNC->nRef;
+
         if( pItem->zName ) pParse->zAuthContext = pItem->zName;
         sqlite3ResolveSelectNames(pParse, pItem->pSelect, pOuterNC);
         pParse->zAuthContext = zSavedContext;
         if( pParse->nErr || db->mallocFailed ) return WRC_Abort;
+
+        for(pNC=pOuterNC; pNC; pNC=pNC->pNext) nRef -= pNC->nRef;
+        assert( pItem->isCorrelated==0 && nRef<=0 );
+        pItem->isCorrelated = (nRef!=0);
       }
     }
   
diff --git a/src/sqliteInt.h b/src/sqliteInt.h
index 9f47ffddec..bcf6a591af 100644
--- a/src/sqliteInt.h
+++ b/src/sqliteInt.h
@@ -1848,6 +1848,7 @@ struct SrcList {
     u8 isPopulated;   /* Temporary table associated with SELECT is populated */
     u8 jointype;      /* Type of join between this able and the previous */
     u8 notIndexed;    /* True if there is a NOT INDEXED clause */
+    u8 isCorrelated;  /* True if sub-query is correlated */
 #ifndef SQLITE_OMIT_EXPLAIN
     u8 iSelectId;     /* If pSelect!=0, the id of the sub-select in EQP */
 #endif
diff --git a/src/where.c b/src/where.c
index 05d955bada..918a3df5d5 100644
--- a/src/where.c
+++ b/src/where.c
@@ -1919,6 +1919,10 @@ static void bestAutomaticIndex(
     /* The NOT INDEXED clause appears in the SQL. */
     return;
   }
+  if( pSrc->isCorrelated ){
+    /* The source is a correlated sub-query. No point in indexing it. */
+    return;
+  }
 
   assert( pParse->nQueryLoop >= (double)1 );
   pTable = pSrc->pTab;
diff --git a/test/tkt-54844eea3f.test b/test/tkt-54844eea3f.test
new file mode 100644
index 0000000000..7b04f6935d
--- /dev/null
+++ b/test/tkt-54844eea3f.test
@@ -0,0 +1,67 @@
+# 2011 July 8
+#
+# 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 bug [54844eea3f] has been fixed.
+#
+
+set testdir [file dirname $argv0]
+source $testdir/tester.tcl
+
+set ::testprefix tkt-54844eea3f
+
+do_test 1.0 {
+  execsql {
+    CREATE TABLE t1(a INTEGER PRIMARY KEY);
+    INSERT INTO t1 VALUES(1);
+    INSERT INTO t1 VALUES(4);
+
+    CREATE TABLE t2(b INTEGER PRIMARY KEY);
+    INSERT INTO t2 VALUES(1);
+    INSERT INTO t2 VALUES(2);
+    INSERT INTO t2 SELECT b+2 FROM t2;
+    INSERT INTO t2 SELECT b+4 FROM t2;
+    INSERT INTO t2 SELECT b+8 FROM t2;
+    INSERT INTO t2 SELECT b+16 FROM t2;
+
+    CREATE TABLE t3(c INTEGER PRIMARY KEY);
+    INSERT INTO t3 VALUES(1);
+    INSERT INTO t3 VALUES(2);
+    INSERT INTO t3 VALUES(3);
+  }
+} {}
+
+do_test 1.1 {
+  execsql {
+    SELECT 'test-2', t3.c, (
+          SELECT count(*) 
+          FROM t1 JOIN (SELECT DISTINCT t3.c AS p FROM t2) AS x ON t1.a=x.p
+    )
+    FROM t3;
+  }
+} {test-2 1 1 test-2 2 0 test-2 3 0}
+
+do_test 1.2 {
+  execsql {
+    CREATE TABLE t4(a, b, c);
+    INSERT INTO t4 VALUES('a', 1, 'one');
+    INSERT INTO t4 VALUES('a', 2, 'two');
+    INSERT INTO t4 VALUES('b', 1, 'three');
+    INSERT INTO t4 VALUES('b', 2, 'four');
+    SELECT ( 
+      SELECT c FROM (
+        SELECT * FROM t4 WHERE a=out.a ORDER BY b LIMIT 10 OFFSET 1
+      ) WHERE b=out.b
+    ) FROM t4 AS out;
+  }
+} {{} two {} four}
+
+
+finish_test