Also free up the MEM_RowSet bit in the Mem.flags field and have RowSet objects

be destroyed using Mem.xDel.  This change results in faster code.

FossilOrigin-Name: f48e9feb3fca514e4e586932e6d19a5e34a384204effeba553006dcddf5f13d2

manifest

@@ -1,5 +1,5 @@
-C Free\sup\sthe\sMEM_Frame\sbit\sin\sMem.flags\sobject.\s\sStore\sVdbeFrame\sobjects\nas\sMEM_Blob\swith\sa\sspecial\sMem.xDel\spointer\sinstead.
+C Also\sfree\sup\sthe\sMEM_RowSet\sbit\sin\sthe\sMem.flags\sfield\sand\shave\sRowSet\sobjects\nbe\sdestroyed\susing\sMem.xDel.\s\sThis\schange\sresults\sin\sfaster\scode.
-D 2018-08-29T18:47:22.883
+D 2018-08-29T20:24:03.572
 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
 F Makefile.in d06f463c5b623a61ac27f5cb8214fca9e53a6704d34d6b8f2124e2b1b293c88f
@@ -499,13 +499,13 @@ F src/prepare.c e966ecc97c3671ff0e96227c8c877b83f2d33ea371ee190bbf1698b36b5605c0
 F src/printf.c 7f6f3cba8e0c49c19e30a1ff4e9aeda6e06814dcbad4b664a69e1b6cb6e7e365
 F src/random.c 80f5d666f23feb3e6665a6ce04c7197212a88384
 F src/resolve.c 797088662ed61102485e3070ba3b3f7828bd5ef6a588223ba6865d77d52f6cea
-F src/rowset.c 7b7e7e479212e65b723bf40128c7b36dc5afdfac
+F src/rowset.c d977b011993aaea002cab3e0bb2ce50cf346000dff94e944d547b989f4b1fe93
 F src/select.c ae7396a314cc1bb1d767947cd57094e3a9ffcbb155ebc1b1c391e028c44a9a04
 F src/shell.c.in 6e0aad854be738a5d0368940459399be211e9ac43aebe92bb9ed46cfe38d0e1f
 F src/sqlite.h.in 5a2d431493020c2c9f2f37c9119d6439444e3c44a714566a5192b6911ac917e6
 F src/sqlite3.rc 5121c9e10c3964d5755191c80dd1180c122fc3a8
 F src/sqlite3ext.h 9887b27e69c01e79c2cbe74ef73bf01af5b5703d6a7f0a4371e386d7249cb1c7
-F src/sqliteInt.h 2a670143a4f6b7d85958bac125e4d9d8ad14f016a3582e9d7c6907d9d50b75a0
+F src/sqliteInt.h 26e48f0c823844fcce67bd2a11ad1ad3468aaed32fd8864bc69c4147cb608728
 F src/sqliteLimit.h 1513bfb7b20378aa0041e7022d04acb73525de35b80b252f1b83fedb4de6a76b
 F src/status.c 46e7aec11f79dad50965a5ca5fa9de009f7d6bde08be2156f1538a0a296d4d0e
 F src/table.c b46ad567748f24a326d9de40e5b9659f96ffff34
@@ -571,13 +571,13 @@ F src/upsert.c 0dd81b40206841814d46942a7337786932475f085716042d0cb2fc7791bf8ca4
 F src/utf.c 810fbfebe12359f10bc2a011520a6e10879ab2a163bcb26c74768eab82ea62a5
 F src/util.c d9eb0a6c4aae1b00a7369eadd7ca0bbe946cb4c953b6751aa20d357c2f482157
 F src/vacuum.c 36e7d21a20c0bf6ef4ef7c399d192b5239410b7c4d3c1070fba4e30810d0b855
-F src/vdbe.c a44a1cd246f808d36ee0ce7dc031d9624a50242db96ac57f65ad93aea65ceaac
+F src/vdbe.c 74671dff9ba856c5464557a8dbf2ba940fc4fa67efbceb32e262eedac31d86ca
 F src/vdbe.h 5081dcc497777efe5e9ebe7330d283a044a005e4bdda2e2e984f03bf89a0d907
-F src/vdbeInt.h a660268d9e60dcd60abe8768c1582dd35f3d174ad12f742aee8c805af72dac03
+F src/vdbeInt.h f1f35f70460698d8f5a2bdef1001114babf318e2983a067804e2ae077d8e9827
 F src/vdbeapi.c 2ba821c5929a2769e4b217dd85843479c718b8989d414723ec8af0616a83d611
-F src/vdbeaux.c 20da0273e9bdb3f49dafa71123d7bdd63b2656134ecd73123562c028847d0e07
+F src/vdbeaux.c 1ee77344fe9fd6ac11fae6f0150f81e0eadf349a9957340089cf82284e6b379a
 F src/vdbeblob.c f5c70f973ea3a9e915d1693278a5f890dc78594300cf4d54e64f2b0917c94191
-F src/vdbemem.c 9a9aa4262f2c5620a552ad83902379d9b1dbb792eb4c1e8758ffffa7ab8a2e64
+F src/vdbemem.c 81329ab760e4ec0162119d9cd10193e0303c45c5935bb20c7ae9139d44dd6641
 F src/vdbesort.c 90aad5a92608f2dd771c96749beabdb562c9d881131a860a7a5bccf66dc3be7f
 F src/vdbetrace.c 79d6dbbc479267b255a7de8080eee6e729928a0ef93ed9b0bfa5618875b48392
 F src/vtab.c 678992ac8ec677a3f9b08126aaf891441083805e3b42574e3654d44538381c14
@@ -1758,7 +1758,7 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P 2d4debccbc027405a33aeb10f9d65f6fe4bfb5eb1be5a4d8b82158caba04643f
+P 62db5fd47660bbc4fcf2c6d4a6c5a3077f12c6442a128d22b66b789a0409ef32
-R bd76e3ebc281873295239e9b6605a092
+R b874f6bc6fe7e6d492c17f3293f43632
 U drh
-Z 6a1519aefdfc6d3a0da507442f0a767b
+Z e2bd09cc55c8cf3a3298f3d931f8e0b9

manifest.uuid

@@ -1 +1 @@
-62db5fd47660bbc4fcf2c6d4a6c5a3077f12c6442a128d22b66b789a0409ef32
+f48e9feb3fca514e4e586932e6d19a5e34a384204effeba553006dcddf5f13d2

src/rowset.c

@@ -124,30 +124,23 @@ struct RowSet {
 #define ROWSET_NEXT    0x02   /* True if sqlite3RowSetNext() has been called */
 
 /*
-** Turn bulk memory into a RowSet object.  N bytes of memory
+** Allocate a RowSet object.  Return NULL if a memory allocation
-** are available at pSpace.  The db pointer is used as a memory context
+** error occurs.
-** for any subsequent allocations that need to occur.
-** Return a pointer to the new RowSet object.
-**
-** It must be the case that N is sufficient to make a Rowset.  If not
-** an assertion fault occurs.
-** 
-** If N is larger than the minimum, use the surplus as an initial
-** allocation of entries available to be filled.
 */
-RowSet *sqlite3RowSetInit(sqlite3 *db, void *pSpace, unsigned int N){
+RowSet *sqlite3RowSetInit(sqlite3 *db){
-  RowSet *p;
+  RowSet *p = sqlite3DbMallocRawNN(db, sizeof(*p));
-  assert( N >= ROUND8(sizeof(*p)) );
+  if( p ){
-  p = pSpace;
+    int N = sqlite3DbMallocSize(db, p);
-  p->pChunk = 0;
+    p->pChunk = 0;
-  p->db = db;
+    p->db = db;
-  p->pEntry = 0;
+    p->pEntry = 0;
-  p->pLast = 0;
+    p->pLast = 0;
-  p->pForest = 0;
+    p->pForest = 0;
-  p->pFresh = (struct RowSetEntry*)(ROUND8(sizeof(*p)) + (char*)p);
+    p->pFresh = (struct RowSetEntry*)(ROUND8(sizeof(*p)) + (char*)p);
-  p->nFresh = (u16)((N - ROUND8(sizeof(*p)))/sizeof(struct RowSetEntry));
+    p->nFresh = (u16)((N - ROUND8(sizeof(*p)))/sizeof(struct RowSetEntry));
-  p->rsFlags = ROWSET_SORTED;
+    p->rsFlags = ROWSET_SORTED;
-  p->iBatch = 0;
+    p->iBatch = 0;
+  }
   return p;
 }
 
@@ -156,7 +149,8 @@ RowSet *sqlite3RowSetInit(sqlite3 *db, void *pSpace, unsigned int N){
 ** the RowSet has allocated over its lifetime.  This routine is
 ** the destructor for the RowSet.
 */
-void sqlite3RowSetClear(RowSet *p){
+void sqlite3RowSetClear(void *pArg){
+  RowSet *p = (RowSet*)pArg;
   struct RowSetChunk *pChunk, *pNextChunk;
   for(pChunk=p->pChunk; pChunk; pChunk = pNextChunk){
     pNextChunk = pChunk->pNextChunk;
@@ -170,6 +164,16 @@ void sqlite3RowSetClear(RowSet *p){
   p->rsFlags = ROWSET_SORTED;
 }
 
+/*
+** Deallocate all chunks from a RowSet.  This frees all memory that
+** the RowSet has allocated over its lifetime.  This routine is
+** the destructor for the RowSet.
+*/
+void sqlite3RowSetDelete(void *pArg){
+  sqlite3RowSetClear(pArg);
+  sqlite3DbFree(((RowSet*)pArg)->db, pArg);
+}
+
 /*
 ** Allocate a new RowSetEntry object that is associated with the
 ** given RowSet.  Return a pointer to the new and completely uninitialized

src/sqliteInt.h

@@ -3825,8 +3825,9 @@ u32 sqlite3BitvecSize(Bitvec*);
 int sqlite3BitvecBuiltinTest(int,int*);
 #endif
 
-RowSet *sqlite3RowSetInit(sqlite3*, void*, unsigned int);
+RowSet *sqlite3RowSetInit(sqlite3*);
-void sqlite3RowSetClear(RowSet*);
+void sqlite3RowSetDelete(void*);
+void sqlite3RowSetClear(void*);
 void sqlite3RowSetInsert(RowSet*, i64);
 int sqlite3RowSetTest(RowSet*, int iBatch, i64);
 int sqlite3RowSetNext(RowSet*, i64*);

src/vdbe.c

@@ -502,7 +502,7 @@ static void memTracePrint(Mem *p){
   }else if( p->flags & MEM_Real ){
     printf(" r:%g", p->u.r);
 #endif
-  }else if( p->flags & MEM_RowSet ){
+  }else if( sqlite3VdbeMemIsRowSet(p) ){
     printf(" (rowset)");
   }else{
     char zBuf[200];
@@ -5903,11 +5903,11 @@ case OP_RowSetAdd: {       /* in1, in2 */
   pIn1 = &aMem[pOp->p1];
   pIn2 = &aMem[pOp->p2];
   assert( (pIn2->flags & MEM_Int)!=0 );
-  if( (pIn1->flags & MEM_RowSet)==0 ){
+  if( (pIn1->flags & MEM_Blob)==0 ){
-    sqlite3VdbeMemSetRowSet(pIn1);
+    if( sqlite3VdbeMemSetRowSet(pIn1) ) goto no_mem;
-    if( (pIn1->flags & MEM_RowSet)==0 ) goto no_mem;
   }
-  sqlite3RowSetInsert(pIn1->u.pRowSet, pIn2->u.i);
+  assert( sqlite3VdbeMemIsRowSet(pIn1) );
+  sqlite3RowSetInsert((RowSet*)pIn1->z, pIn2->u.i);
   break;
 }
 
@@ -5923,8 +5923,9 @@ case OP_RowSetRead: {       /* jump, in1, out3 */
   i64 val;
 
   pIn1 = &aMem[pOp->p1];
-  if( (pIn1->flags & MEM_RowSet)==0 
+  assert( (pIn1->flags & MEM_Blob)==0 || sqlite3VdbeMemIsRowSet(pIn1) );
-   || sqlite3RowSetNext(pIn1->u.pRowSet, &val)==0
+  if( (pIn1->flags & MEM_Blob)==0 
+   || sqlite3RowSetNext((RowSet*)pIn1->z, &val)==0
   ){
     /* The boolean index is empty */
     sqlite3VdbeMemSetNull(pIn1);
@@ -5973,20 +5974,19 @@ case OP_RowSetTest: {                     /* jump, in1, in3 */
   /* If there is anything other than a rowset object in memory cell P1,
   ** delete it now and initialize P1 with an empty rowset
   */
-  if( (pIn1->flags & MEM_RowSet)==0 ){
+  if( (pIn1->flags & MEM_Blob)==0 ){
-    sqlite3VdbeMemSetRowSet(pIn1);
+    if( sqlite3VdbeMemSetRowSet(pIn1) ) goto no_mem;
-    if( (pIn1->flags & MEM_RowSet)==0 ) goto no_mem;
   }
-
+  assert( sqlite3VdbeMemIsRowSet(pIn1) );
   assert( pOp->p4type==P4_INT32 );
   assert( iSet==-1 || iSet>=0 );
   if( iSet ){
-    exists = sqlite3RowSetTest(pIn1->u.pRowSet, iSet, pIn3->u.i);
+    exists = sqlite3RowSetTest((RowSet*)pIn1->z, iSet, pIn3->u.i);
     VdbeBranchTaken(exists!=0,2);
     if( exists ) goto jump_to_p2;
   }
   if( iSet>=0 ){
-    sqlite3RowSetInsert(pIn1->u.pRowSet, pIn3->u.i);
+    sqlite3RowSetInsert((RowSet*)pIn1->z, pIn3->u.i);
   }
   break;
 }

src/vdbeInt.h

@@ -203,7 +203,6 @@ struct sqlite3_value {
     int nZero;          /* Extra zero bytes when MEM_Zero and MEM_Blob set */
     const char *zPType; /* Pointer type when MEM_Term|MEM_Subtype|MEM_Null */
     FuncDef *pDef;      /* Used only when flags==MEM_Agg */
-    RowSet *pRowSet;    /* Used only when flags==MEM_RowSet */
   } u;
   u16 flags;          /* Some combination of MEM_Null, MEM_Str, MEM_Dyn, etc. */
   u8  enc;            /* SQLITE_UTF8, SQLITE_UTF16BE, SQLITE_UTF16LE */
@@ -247,7 +246,7 @@ struct sqlite3_value {
 #define MEM_Real      0x0008   /* Value is a real number */
 #define MEM_Blob      0x0010   /* Value is a BLOB */
 #define MEM_AffMask   0x001f   /* Mask of affinity bits */
-#define MEM_RowSet    0x0020   /* Value is a RowSet object */
+/* Available          0x0020   */
 /* Available          0x0040   */
 #define MEM_Undefined 0x0080   /* Value is undefined */
 #define MEM_Cleared   0x0100   /* NULL set by OP_Null, not from data */
@@ -275,7 +274,7 @@ struct sqlite3_value {
 ** that needs to be deallocated to avoid a leak.
 */
 #define VdbeMemDynamic(X)  \
-  (((X)->flags&(MEM_Agg|MEM_Dyn|MEM_RowSet))!=0)
+  (((X)->flags&(MEM_Agg|MEM_Dyn))!=0)
 
 /*
 ** Clear any existing type flags from a Mem and replace them with f
@@ -488,7 +487,10 @@ void sqlite3VdbeMemSetPointer(Mem*, void*, const char*, void(*)(void*));
 void sqlite3VdbeMemInit(Mem*,sqlite3*,u16);
 void sqlite3VdbeMemSetNull(Mem*);
 void sqlite3VdbeMemSetZeroBlob(Mem*,int);
-void sqlite3VdbeMemSetRowSet(Mem*);
+#ifdef SQLITE_DEBUG
+int sqlite3VdbeMemIsRowSet(const Mem*);
+#endif
+int sqlite3VdbeMemSetRowSet(Mem*);
 int sqlite3VdbeMemMakeWriteable(Mem*);
 int sqlite3VdbeMemStringify(Mem*, u8, u8);
 i64 sqlite3VdbeIntValue(Mem*);

src/vdbeaux.c

@@ -1663,7 +1663,7 @@ static void releaseMemArray(Mem *p, int N){
       testcase( p->flags & MEM_Dyn );
       testcase( p->xDel==sqlite3VdbeFrameMemDel );
       testcase( p->flags & MEM_RowSet );
-      if( p->flags&(MEM_Agg|MEM_Dyn|MEM_RowSet) ){
+      if( p->flags&(MEM_Agg|MEM_Dyn) ){
         sqlite3VdbeMemRelease(p);
       }else if( p->szMalloc ){
         sqlite3DbFreeNN(db, p->zMalloc);
@@ -3991,7 +3991,7 @@ int sqlite3MemCompare(const Mem *pMem1, const Mem *pMem2, const CollSeq *pColl){
   f1 = pMem1->flags;
   f2 = pMem2->flags;
   combined_flags = f1|f2;
-  assert( (combined_flags & MEM_RowSet)==0 );
+  assert( !sqlite3VdbeMemIsRowSet(pMem1) && !sqlite3VdbeMemIsRowSet(pMem2) );
  
   /* If one value is NULL, it is less than the other. If both values
   ** are NULL, return 0.

src/vdbemem.c

@@ -42,8 +42,7 @@ int sqlite3VdbeCheckMemInvariants(Mem *p){
 
   if( p->flags & MEM_Null ){
     /* Cannot be both MEM_Null and some other type */
-    assert( (p->flags & (MEM_Int|MEM_Real|MEM_Str|MEM_Blob
+    assert( (p->flags & (MEM_Int|MEM_Real|MEM_Str|MEM_Blob|MEM_Agg))==0 );
-                         |MEM_RowSet|MEM_Agg))==0 );
 
     /* If MEM_Null is set, then either the value is a pure NULL (the usual
     ** case) or it is a pointer set using sqlite3_bind_pointer() or
@@ -156,7 +155,7 @@ int sqlite3VdbeChangeEncoding(Mem *pMem, int desiredEnc){
 #ifndef SQLITE_OMIT_UTF16
   int rc;
 #endif
-  assert( (pMem->flags&MEM_RowSet)==0 );
+  assert( !sqlite3VdbeMemIsRowSet(pMem) );
   assert( desiredEnc==SQLITE_UTF8 || desiredEnc==SQLITE_UTF16LE
            || desiredEnc==SQLITE_UTF16BE );
   if( !(pMem->flags&MEM_Str) || pMem->enc==desiredEnc ){
@@ -189,7 +188,7 @@ int sqlite3VdbeChangeEncoding(Mem *pMem, int desiredEnc){
 */
 SQLITE_NOINLINE int sqlite3VdbeMemGrow(Mem *pMem, int n, int bPreserve){
   assert( sqlite3VdbeCheckMemInvariants(pMem) );
-  assert( (pMem->flags&MEM_RowSet)==0 );
+  assert( !sqlite3VdbeMemIsRowSet(pMem) );
   testcase( pMem->db==0 );
 
   /* If the bPreserve flag is set to true, then the memory cell must already
@@ -277,7 +276,7 @@ static SQLITE_NOINLINE int vdbeMemAddTerminator(Mem *pMem){
 */
 int sqlite3VdbeMemMakeWriteable(Mem *pMem){
   assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );
-  assert( (pMem->flags&MEM_RowSet)==0 );
+  assert( !sqlite3VdbeMemIsRowSet(pMem) );
   if( (pMem->flags & (MEM_Str|MEM_Blob))!=0 ){
     if( ExpandBlob(pMem) ) return SQLITE_NOMEM;
     if( pMem->szMalloc==0 || pMem->z!=pMem->zMalloc ){
@@ -302,7 +301,7 @@ int sqlite3VdbeMemExpandBlob(Mem *pMem){
   int nByte;
   assert( pMem->flags & MEM_Zero );
   assert( pMem->flags&MEM_Blob );
-  assert( (pMem->flags&MEM_RowSet)==0 );
+  assert( !sqlite3VdbeMemIsRowSet(pMem) );
   assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );
 
   /* Set nByte to the number of bytes required to store the expanded blob. */
@@ -357,7 +356,7 @@ int sqlite3VdbeMemStringify(Mem *pMem, u8 enc, u8 bForce){
   assert( !(fg&MEM_Zero) );
   assert( !(fg&(MEM_Str|MEM_Blob)) );
   assert( fg&(MEM_Int|MEM_Real) );
-  assert( (pMem->flags&MEM_RowSet)==0 );
+  assert( !sqlite3VdbeMemIsRowSet(pMem) );
   assert( EIGHT_BYTE_ALIGNMENT(pMem) );
 
 
@@ -462,11 +461,8 @@ static SQLITE_NOINLINE void vdbeMemClearExternAndSetNull(Mem *p){
     testcase( p->flags & MEM_Dyn );
   }
   if( p->flags&MEM_Dyn ){
-    assert( (p->flags&MEM_RowSet)==0 );
     assert( p->xDel!=SQLITE_DYNAMIC && p->xDel!=0 );
     p->xDel((void *)p->z);
-  }else if( p->flags&MEM_RowSet ){
-    sqlite3RowSetClear(p->u.pRowSet);
   }
   p->flags = MEM_Null;
 }
@@ -614,7 +610,7 @@ int sqlite3VdbeBooleanValue(Mem *pMem, int ifNull){
 void sqlite3VdbeIntegerAffinity(Mem *pMem){
   i64 ix;
   assert( pMem->flags & MEM_Real );
-  assert( (pMem->flags & MEM_RowSet)==0 );
+  assert( !sqlite3VdbeMemIsRowSet(pMem) );
   assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );
   assert( EIGHT_BYTE_ALIGNMENT(pMem) );
 
@@ -641,7 +637,7 @@ void sqlite3VdbeIntegerAffinity(Mem *pMem){
 */
 int sqlite3VdbeMemIntegerify(Mem *pMem){
   assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );
-  assert( (pMem->flags & MEM_RowSet)==0 );
+  assert( !sqlite3VdbeMemIsRowSet(pMem) );
   assert( EIGHT_BYTE_ALIGNMENT(pMem) );
 
   pMem->u.i = sqlite3VdbeIntValue(pMem);
@@ -859,26 +855,36 @@ void sqlite3VdbeMemSetDouble(Mem *pMem, double val){
 }
 #endif
 
+#ifdef SQLITE_DEBUG
+/*
+** Return true if the Mem holds a RowSet object.  This routine is intended
+** for use inside of assert() statements.
+*/
+int sqlite3VdbeMemIsRowSet(const Mem *pMem){
+  return (pMem->flags&(MEM_Blob|MEM_Dyn))==(MEM_Blob|MEM_Dyn)
+         && pMem->xDel==sqlite3RowSetDelete;
+}
+#endif
+
 /*
 ** Delete any previous value and set the value of pMem to be an
 ** empty boolean index.
+**
+** Return SQLITE_OK on success and SQLITE_NOMEM if a memory allocation
+** error occurs.
 */
-void sqlite3VdbeMemSetRowSet(Mem *pMem){
+int sqlite3VdbeMemSetRowSet(Mem *pMem){
   sqlite3 *db = pMem->db;
+  RowSet *p;
   assert( db!=0 );
-  assert( (pMem->flags & MEM_RowSet)==0 );
+  assert( !sqlite3VdbeMemIsRowSet(pMem) );
   sqlite3VdbeMemRelease(pMem);
-  pMem->zMalloc = sqlite3DbMallocRawNN(db, 64);
+  p = sqlite3RowSetInit(db);
-  if( db->mallocFailed ){
+  if( p==0 ) return SQLITE_NOMEM;
-    pMem->flags = MEM_Null;
+  pMem->z = (char*)p;
-    pMem->szMalloc = 0;
+  pMem->flags = MEM_Blob|MEM_Dyn;
-  }else{
+  pMem->xDel = sqlite3RowSetDelete;
-    assert( pMem->zMalloc );
+  return SQLITE_OK;
-    pMem->szMalloc = sqlite3DbMallocSize(db, pMem->zMalloc);
-    pMem->u.pRowSet = sqlite3RowSetInit(db, pMem->zMalloc, pMem->szMalloc);
-    assert( pMem->u.pRowSet!=0 );
-    pMem->flags = MEM_RowSet;
-  }
 }
 
 /*
@@ -946,7 +952,7 @@ static SQLITE_NOINLINE void vdbeClrCopy(Mem *pTo, const Mem *pFrom, int eType){
   sqlite3VdbeMemShallowCopy(pTo, pFrom, eType);
 }
 void sqlite3VdbeMemShallowCopy(Mem *pTo, const Mem *pFrom, int srcType){
-  assert( (pFrom->flags & MEM_RowSet)==0 );
+  assert( !sqlite3VdbeMemIsRowSet(pFrom) );
   assert( pTo->db==pFrom->db );
   if( VdbeMemDynamic(pTo) ){ vdbeClrCopy(pTo,pFrom,srcType); return; }
   memcpy(pTo, pFrom, MEMCELLSIZE);
@@ -964,7 +970,7 @@ void sqlite3VdbeMemShallowCopy(Mem *pTo, const Mem *pFrom, int srcType){
 int sqlite3VdbeMemCopy(Mem *pTo, const Mem *pFrom){
   int rc = SQLITE_OK;
 
-  assert( (pFrom->flags & MEM_RowSet)==0 );
+  assert( !sqlite3VdbeMemIsRowSet(pFrom) );
   if( VdbeMemDynamic(pTo) ) vdbeMemClearExternAndSetNull(pTo);
   memcpy(pTo, pFrom, MEMCELLSIZE);
   pTo->flags &= ~MEM_Dyn;
@@ -1022,7 +1028,7 @@ int sqlite3VdbeMemSetStr(
   u16 flags = 0;      /* New value for pMem->flags */
 
   assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );
-  assert( (pMem->flags & MEM_RowSet)==0 );
+  assert( !sqlite3VdbeMemIsRowSet(pMem) );
 
   /* If z is a NULL pointer, set pMem to contain an SQL NULL. */
   if( !z ){
@@ -1144,7 +1150,7 @@ int sqlite3VdbeMemFromBtree(
 
   /* Note: the calls to BtreeKeyFetch() and DataFetch() below assert() 
   ** that both the BtShared and database handle mutexes are held. */
-  assert( (pMem->flags & MEM_RowSet)==0 );
+  assert( !sqlite3VdbeMemIsRowSet(pMem) );
   zData = (char *)sqlite3BtreePayloadFetch(pCur, &available);
   assert( zData!=0 );
 
@@ -1168,7 +1174,7 @@ static SQLITE_NOINLINE const void *valueToText(sqlite3_value* pVal, u8 enc){
   assert( pVal!=0 );
   assert( pVal->db==0 || sqlite3_mutex_held(pVal->db->mutex) );
   assert( (enc&3)==(enc&~SQLITE_UTF16_ALIGNED) );
-  assert( (pVal->flags & MEM_RowSet)==0 );
+  assert( !sqlite3VdbeMemIsRowSet(pVal) );
   assert( (pVal->flags & (MEM_Null))==0 );
   if( pVal->flags & (MEM_Blob|MEM_Str) ){
     if( ExpandBlob(pVal) ) return 0;
@@ -1211,7 +1217,7 @@ const void *sqlite3ValueText(sqlite3_value* pVal, u8 enc){
   if( !pVal ) return 0;
   assert( pVal->db==0 || sqlite3_mutex_held(pVal->db->mutex) );
   assert( (enc&3)==(enc&~SQLITE_UTF16_ALIGNED) );
-  assert( (pVal->flags & MEM_RowSet)==0 );
+  assert( !sqlite3VdbeMemIsRowSet(pVal) );
   if( (pVal->flags&(MEM_Str|MEM_Term))==(MEM_Str|MEM_Term) && pVal->enc==enc ){
     assert( sqlite3VdbeMemConsistentDualRep(pVal) );
     return pVal->z;