Add a pragma to disable the query flattener - for use during testing.

FossilOrigin-Name: 1d8550e5c88db0ea76aea579c1a5bf99d48fbe43

manifest

@@ -1,5 +1,8 @@
-C Change\smany\scomments\sin\se_fkey.test\sto\sinclude\sthe\sfull\stext\sof\sthe\scorresponding\sstatement\sin\sforeignkeys.html.
-D 2009-12-21T08:53:18
+-----BEGIN PGP SIGNED MESSAGE-----
+Hash: SHA1
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+C Add\sa\spragma\sto\sdisable\sthe\squery\sflattener\s-\sfor\suse\sduring\stesting.
+D 2009-12-22T00:29:53
 F Makefile.arm-wince-mingw32ce-gcc fcd5e9cd67fe88836360bb4f9ef4cb7f8e2fb5a0
 F Makefile.in c5827ead754ab32b9585487177c93bb00b9497b3
 F Makefile.linux-gcc d53183f4aa6a9192d249731c90dbdffbd2c68654
@@ -156,17 +159,17 @@ F src/parse.y ace5c7a125d9f2a410e431ee3209034105045f7e
 F src/pcache.c 3b079306376e0e04c0d3df40c0a4b750a1839310
 F src/pcache.h c683390d50f856d4cd8e24342ae62027d1bb6050
 F src/pcache1.c 2bb2261190b42a348038f5b1c285c8cef415fcc8
-F src/pragma.c 6936d7df5e04b9f996f8f320d15e65b6944b2caa
+F src/pragma.c c194fc135754c700fefc6f7fbe77e90b1dc40aff
 F src/prepare.c 170bd953058efe1c46b8ad9020d49cd6f40f0b45
 F src/printf.c 644bc7d59df3dc56d6d8b9a510914bfc6b51bc69
 F src/random.c cd4a67b3953b88019f8cd4ccd81394a8ddfaba50
 F src/resolve.c d052e5c44bab34f83b3c1741aaa07478d18b5dd5
 F src/rowset.c 69afa95a97c524ba6faf3805e717b5b7ae85a697
-F src/select.c 68c58dc49341472e4e5661a47a1a9e5f8a161340
+F src/select.c 9b5ad0e12b2a95fe9cf48d383b6fec5ca31b6a72
 F src/shell.c b9fae60b0f2ce306c20fa99e83c75023bf35f15b
 F src/sqlite.h.in 176e993dce3c9cfe5610aca0ef99f4dfd70896bb
 F src/sqlite3ext.h 69dfb8116af51b84a029cddb3b35062354270c89
-F src/sqliteInt.h 93d5d01d9ea57b95ba709733dce830ec056deb84
+F src/sqliteInt.h eddc248fb88d76f0c77be45fa72099c48af243af
 F src/sqliteLimit.h 3afab2291762b5d09ae20c18feb8e9fa935a60a6
 F src/status.c e651be6b30d397d86384c6867bc016e4913bcac7
 F src/table.c 2cd62736f845d82200acfa1287e33feb3c15d62e
@@ -782,7 +785,14 @@ F tool/speedtest2.tcl ee2149167303ba8e95af97873c575c3e0fab58ff
 F tool/speedtest8.c 2902c46588c40b55661e471d7a86e4dd71a18224
 F tool/speedtest8inst1.c 293327bc76823f473684d589a8160bde1f52c14e
 F tool/vdbe-compress.tcl d70ea6d8a19e3571d7ab8c9b75cba86d1173ff0f
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-U dan
-Z e3737637173861a53abcf3ec5e22169c
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+U drh
+Z a149efdbc300f2ef9c4bcc0e34bf2979
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manifest.uuid

@@ -1 +1 @@
-4b489ecb250ea0e80d5bf8806f07259e1107f8ad
+1d8550e5c88db0ea76aea579c1a5bf99d48fbe43

src/pragma.c

@@ -185,6 +185,9 @@ static int flagPragma(Parse *pParse, const char *zLeft, const char *zRight){
     { "writable_schema",          SQLITE_WriteSchema|SQLITE_RecoveryMode },
     { "omit_readlock",            SQLITE_NoReadlock    },
 
+    /* For testing purposes only */
+    { "omit_flattener",           SQLITE_OmitFlattener },
+
     /* TODO: Maybe it shouldn't be possible to change the ReadUncommitted
     ** flag if there are any active statements. */
     { "read_uncommitted",         SQLITE_ReadUncommitted },

src/select.c

@@ -957,7 +957,7 @@ static const char *columnType(
         ** of the SELECT statement. Return the declaration type and origin
         ** data for the result-set column of the sub-select.
         */
-        if( ALWAYS(iCol>=0 && iCol<pS->pEList->nExpr) ){
+        if( iCol>=0 && ALWAYS(iCol<pS->pEList->nExpr) ){
           /* If iCol is less than zero, then the expression requests the
           ** rowid of the sub-select or view. This expression is legal (see 
           ** test case misc2.2.2) - it always evaluates to NULL.
@@ -2518,7 +2518,7 @@ static void substSelect(
 **
 **  (11)  The subquery and the outer query do not both have ORDER BY clauses.
 **
-**  (12)  Not implemented.  Subsumed into restriction (3).  Was previously
+**  (**)  Not implemented.  Subsumed into restriction (3).  Was previously
 **        a separate restriction deriving from ticket #350.
 **
 **  (13)  The subquery and outer query do not both use LIMIT
@@ -2592,6 +2592,13 @@ static int flattenSubquery(
   */
   assert( p!=0 );
   assert( p->pPrior==0 );  /* Unable to flatten compound queries */
+
+  /* The "PRAGMA omit_flattener=ON" statement disables query flattening for
+  ** testing purposes.  The only reason to disable the query flattener is
+  ** to verify that we get the same answer with and without the flattener.
+  ** In production use, there is never a reason to turn the flattener off. */
+  if( db->flags & SQLITE_OmitFlattener ) return 0;
+
   pSrc = p->pSrc;
   assert( pSrc && iFrom>=0 && iFrom<pSrc->nSrc );
   pSubitem = &pSrc->a[iFrom];

src/sqliteInt.h

@@ -920,15 +920,15 @@ struct sqlite3 {
 #define SQLITE_NoReadlock     0x00001000  /* Readlocks are omitted when 
                                           ** accessing read-only databases */
 #define SQLITE_IgnoreChecks   0x00002000  /* Do not enforce check constraints */
-#define SQLITE_ReadUncommitted 0x00004000 /* For shared-cache mode */
+#define SQLITE_ReadUncommitted 0x0004000  /* For shared-cache mode */
 #define SQLITE_LegacyFileFmt  0x00008000  /* Create new databases in format 1 */
 #define SQLITE_FullFSync      0x00010000  /* Use full fsync on the backend */
 #define SQLITE_LoadExtension  0x00020000  /* Enable load_extension */
-
 #define SQLITE_RecoveryMode   0x00040000  /* Ignore schema errors */
 #define SQLITE_ReverseOrder   0x00100000  /* Reverse unordered SELECTs */
 #define SQLITE_RecTriggers    0x00200000  /* Enable recursive triggers */
-#define SQLITE_ForeignKeys    0x00400000  /* Enforce foreign key constraints  */
+#define SQLITE_ForeignKeys    0x00400000  /* Enforce foreign key constraints */
+#define SQLITE_OmitFlattener  0x00800000  /* Do not flatten queries */
 
 /*
 ** Possible values for the sqlite.magic field.