Index: src/sqliteInt.h
==================================================================
--- src/sqliteInt.h
+++ src/sqliteInt.h
@@ -365,21 +365,10 @@
 #endif
 #if defined(NDEBUG) && defined(SQLITE_DEBUG)
 # undef NDEBUG
 #endif
 
-/* SQLITE_DEBUG_COLUMNCACHE is synomous with SQLITE_DEBUG.  The 
-** SQLITE_DEBUG_COLUMNCACHE symbol only exists to provide a convenient
-** way to search for all code that deals with verifying correct behavior
-** of the column cache.
-*/
-#ifdef SQLITE_DEBUG
-# define SQLITE_DEBUG_COLUMNCACHE 1
-#else
-# undef SQLIT_DEBUG_COLUMNCACHE
-#endif
-
 /*
 ** Enable SQLITE_ENABLE_EXPLAIN_COMMENTS if SQLITE_DEBUG is turned on.
 */
 #if !defined(SQLITE_ENABLE_EXPLAIN_COMMENTS) && defined(SQLITE_DEBUG)
 # define SQLITE_ENABLE_EXPLAIN_COMMENTS 1

Index: src/vdbe.c
==================================================================
--- src/vdbe.c
+++ src/vdbe.c
@@ -34,22 +34,10 @@
 # define memAboutToChange(P,M) sqlite3VdbeMemAboutToChange(P,M)
 #else
 # define memAboutToChange(P,M)
 #endif
 
-/*
-** Given a cursor number and a column for a table or index, compute a
-** hash value for use in the Mem.iTabColHash value.  The iTabColHash
-** column is only used for verification - it is omitted from production
-** builds.  Collisions are harmless in the sense that the correct answer
-** still results.  The only harm of collisions is that they can potential
-** reduce column-cache error detection during SQLITE_DEBUG builds.
-**
-** No valid hash should be 0.
-*/
-#define TableColumnHash(T,C)  (((u32)(T)<<16)^(u32)(C+2))
-
 /*
 ** The following global variable is incremented every time a cursor
 ** moves, either by the OP_SeekXX, OP_Next, or OP_Prev opcodes.  The test
 ** procedures use this information to make sure that indices are
 ** working correctly.  This variable has no function other than to
@@ -1306,11 +1294,10 @@
     memAboutToChange(p, pOut);
     sqlite3VdbeMemShallowCopy(pOut, pIn1, MEM_Ephem);
     Deephemeralize(pOut);
 #ifdef SQLITE_DEBUG
     pOut->pScopyFrom = 0;
-    pOut->iTabColHash = 0;
 #endif
     REGISTER_TRACE(pOp->p2+pOp->p3-n, pOut);
     if( (n--)==0 ) break;
     pOut++;
     pIn1++;
@@ -7442,38 +7429,10 @@
 */
 case OP_Abortable: {
   sqlite3VdbeAssertAbortable(p);
   break;
 }
-#endif
-
-#ifdef SQLITE_DEBUG_COLUMNCACHE
-/* Opcode:  SetTabCol   P1 P2 P3 * *
-**
-** Set a flag in register REG[P3] indicating that it holds the value
-** of column P2 from the table on cursor P1.  This flag is checked
-** by a subsequent VerifyTabCol opcode.
-**
-** This opcode only appears SQLITE_DEBUG builds.  It is used to verify
-** that the expression table column cache is working correctly.
-*/
-case OP_SetTabCol: {
-  aMem[pOp->p3].iTabColHash = TableColumnHash(pOp->p1,pOp->p2);
-  break;
-}
-/* Opcode:  VerifyTabCol   P1 P2 P3 * *
-**
-** Verify that register REG[P3] contains the value of column P2 from
-** cursor P1.  Assert() if this is not the case.
-**
-** This opcode only appears SQLITE_DEBUG builds.  It is used to verify
-** that the expression table column cache is working correctly.
-*/
-case OP_VerifyTabCol: {
-  assert( aMem[pOp->p3].iTabColHash == TableColumnHash(pOp->p1,pOp->p2) );
-  break;
-}
 #endif
 
 /* Opcode: Noop * * * * *
 **
 ** Do nothing.  This instruction is often useful as a jump

Index: src/vdbeInt.h
==================================================================
--- src/vdbeInt.h
+++ src/vdbeInt.h
@@ -209,14 +209,10 @@
   void (*xDel)(void*);/* Destructor for Mem.z - only valid if MEM_Dyn */
 #ifdef SQLITE_DEBUG
   Mem *pScopyFrom;    /* This Mem is a shallow copy of pScopyFrom */
   u16 mScopyFlags;    /* flags value immediately after the shallow copy */
 #endif
-#ifdef SQLITE_DEBUG_COLUMNCACHE
-  u32 iTabColHash;    /* Hash of table.column that is origin of this value */
-  u32 iPadding;       /* sqlite3_value objects must be 8-byte aligned */
-#endif
 };
 
 /*
 ** Size of struct Mem not including the Mem.zMalloc member or anything that
 ** follows.

Index: src/vdbeapi.c
==================================================================
--- src/vdbeapi.c
+++ src/vdbeapi.c
@@ -970,13 +970,10 @@
         /* .xDel       = */ (void(*)(void*))0,
 #ifdef SQLITE_DEBUG
         /* .pScopyFrom = */ (Mem*)0,
         /* .mScopyFlags= */ 0,
 #endif
-#ifdef SQLITE_DEBUG_COLUMNCACHE
-        /* .iTabColHash= */ 0,
-#endif
       };
   return &nullMem;
 }
 
 /*

Index: src/vdbeaux.c
==================================================================
--- src/vdbeaux.c
+++ src/vdbeaux.c
@@ -1637,13 +1637,10 @@
     p->flags = flags;
     p->szMalloc = 0;
 #ifdef SQLITE_DEBUG
     p->pScopyFrom = 0;
 #endif
-#ifdef SQLITE_DEBUG_COLUMNCACHE
-    p->iTabColHash = 0;
-#endif
     p++;
   }
 }
 
 /*

Index: src/vdbemem.c
==================================================================
--- src/vdbemem.c
+++ src/vdbemem.c
@@ -932,13 +932,10 @@
       pX->flags = MEM_Undefined;
       pX->pScopyFrom = 0;
     }
   }
   pMem->pScopyFrom = 0;
-#ifdef SQLITE_DEBUG_COLUMN_CACHE
-  pMem->iTabColHash = 0;
-#endif
 }
 #endif /* SQLITE_DEBUG */
 
 
 /*
@@ -955,13 +952,10 @@
 void sqlite3VdbeMemShallowCopy(Mem *pTo, const Mem *pFrom, int srcType){
   assert( (pFrom->flags & MEM_RowSet)==0 );
   assert( pTo->db==pFrom->db );
   if( VdbeMemDynamic(pTo) ){ vdbeClrCopy(pTo,pFrom,srcType); return; }
   memcpy(pTo, pFrom, MEMCELLSIZE);
-#ifdef SQLITE_DEBUG_COLUMNCACHE
-  pTo->iTabColHash = pFrom->iTabColHash;
-#endif
   if( (pFrom->flags&MEM_Static)==0 ){
     pTo->flags &= ~(MEM_Dyn|MEM_Static|MEM_Ephem);
     assert( srcType==MEM_Ephem || srcType==MEM_Static );
     pTo->flags |= srcType;
   }
@@ -975,13 +969,10 @@
   int rc = SQLITE_OK;
 
   assert( (pFrom->flags & MEM_RowSet)==0 );
   if( VdbeMemDynamic(pTo) ) vdbeMemClearExternAndSetNull(pTo);
   memcpy(pTo, pFrom, MEMCELLSIZE);
-#ifdef SQLITE_DEBUG_COLUMNCACHE
-  pTo->iTabColHash = pFrom->iTabColHash;
-#endif
   pTo->flags &= ~MEM_Dyn;
   if( pTo->flags&(MEM_Str|MEM_Blob) ){
     if( 0==(pFrom->flags&MEM_Static) ){
       pTo->flags |= MEM_Ephem;
       rc = sqlite3VdbeMemMakeWriteable(pTo);