Index: src/select.c
==================================================================
--- src/select.c
+++ src/select.c
@@ -486,21 +486,19 @@
     pParse->nMem += pSort->nOBSat;
     nKey = nExpr - pSort->nOBSat + 1;
     addrFirst = sqlite3VdbeAddOp1(v, OP_IfNot, regBase+nExpr); VdbeCoverage(v);
     sqlite3VdbeAddOp3(v, OP_Compare, regPrevKey, regBase, pSort->nOBSat);
     pOp = sqlite3VdbeGetOp(v, pSort->addrSortIndex);
-    pOp->opcode = OP_OpenEphemeral;
-    pSort->sortFlags &= ~SORTFLAG_UseSorter;
     pOp->p2 = nKey + 1;
     sqlite3VdbeChangeP4(v, -1, (char*)pOp->p4.pKeyInfo, P4_KEYINFO);
     pOp->p4.pKeyInfo = keyInfoFromExprList(pParse, pSort->pOrderBy, nOBSat, 1);
     addrJmp = sqlite3VdbeCurrentAddr(v);
     sqlite3VdbeAddOp3(v, OP_Jump, addrJmp+1, 0, addrJmp+1); VdbeCoverage(v);
     pSort->labelBkOut = sqlite3VdbeMakeLabel(v);
     pSort->regReturn = ++pParse->nMem;
     sqlite3VdbeAddOp2(v, OP_Gosub, pSort->regReturn, pSort->labelBkOut);
-    sqlite3VdbeAddOp1(v, OP_ClearEphem, pSort->iECursor);
+    sqlite3VdbeAddOp1(v, OP_ResetSorter, pSort->iECursor);
     sqlite3VdbeJumpHere(v, addrFirst);
     sqlite3VdbeAddOp3(v, OP_Move, regBase, regPrevKey, pSort->nOBSat);
     sqlite3VdbeJumpHere(v, addrJmp);
   }
   if( pSort->sortFlags & SORTFLAG_UseSorter ){

Index: src/vdbe.c
==================================================================
--- src/vdbe.c
+++ src/vdbe.c
@@ -4870,24 +4870,30 @@
     }
   }
   break;
 }
 
-/* Opcode: ClearEphem P1 * * * *
+/* Opcode: ResetSorter P1 * * * *
 **
-** Delete all contents from the ephemeral table that is open on cursor P1.
+** Delete all contents from the ephemeral table or sorter
+** that is open on cursor P1.
 **
-** See also: Clear, Destroy
+** This opcode only works for cursors used for sorting and
+** opened with OP_OpenEphemeral or OP_SorterOpen.
 */
-case OP_ClearEphem: {
+case OP_ResetSorter: {
   VdbeCursor *pC;
  
   assert( pOp->p1>=0 && pOp->p1<p->nCursor );
   pC = p->apCsr[pOp->p1];
   assert( pC!=0 );
-  assert( pC->isEphemeral );
-  rc = sqlite3BtreeClearTableOfCursor(pC->pCursor);
+  if( pC->pSorter ){
+    sqlite3VdbeSorterReset(db, pC->pSorter);
+  }else{
+    assert( pC->isEphemeral );
+    rc = sqlite3BtreeClearTableOfCursor(pC->pCursor);
+  }
   break;
 }
 
 /* Opcode: CreateTable P1 P2 * * *
 ** Synopsis: r[P2]=root iDb=P1

Index: src/vdbeInt.h
==================================================================
--- src/vdbeInt.h
+++ src/vdbeInt.h
@@ -436,10 +436,11 @@
 void sqlite3VdbeFrameDelete(VdbeFrame*);
 int sqlite3VdbeFrameRestore(VdbeFrame *);
 int sqlite3VdbeTransferError(Vdbe *p);
 
 int sqlite3VdbeSorterInit(sqlite3 *, VdbeCursor *);
+void sqlite3VdbeSorterReset(sqlite3 *, VdbeSorter *);
 void sqlite3VdbeSorterClose(sqlite3 *, VdbeCursor *);
 int sqlite3VdbeSorterRowkey(const VdbeCursor *, Mem *);
 int sqlite3VdbeSorterNext(sqlite3 *, const VdbeCursor *, int *);
 int sqlite3VdbeSorterRewind(sqlite3 *, const VdbeCursor *, int *);
 int sqlite3VdbeSorterWrite(sqlite3 *, const VdbeCursor *, Mem *);

Index: src/vdbesort.c
==================================================================
--- src/vdbesort.c
+++ src/vdbesort.c
@@ -501,28 +501,45 @@
   for(p=pRecord; p; p=pNext){
     pNext = p->pNext;
     sqlite3DbFree(db, p);
   }
 }
+
+/*
+** Reset a sorting cursor back to its original empty state.
+*/
+void sqlite3VdbeSorterReset(sqlite3 *db, VdbeSorter *pSorter){
+  if( pSorter->aIter ){
+    int i;
+    for(i=0; i<pSorter->nTree; i++){
+      vdbeSorterIterZero(db, &pSorter->aIter[i]);
+    }
+    sqlite3DbFree(db, pSorter->aIter);
+    pSorter->aIter = 0;
+  }
+  if( pSorter->pTemp1 ){
+    sqlite3OsCloseFree(pSorter->pTemp1);
+    pSorter->pTemp1 = 0;
+  }
+  vdbeSorterRecordFree(db, pSorter->pRecord);
+  pSorter->pRecord = 0;
+  pSorter->iWriteOff = 0;
+  pSorter->iReadOff = 0;
+  pSorter->nInMemory = 0;
+  pSorter->nTree = 0;
+  pSorter->nPMA = 0;
+  pSorter->aTree = 0;
+}
+
 
 /*
 ** Free any cursor components allocated by sqlite3VdbeSorterXXX routines.
 */
 void sqlite3VdbeSorterClose(sqlite3 *db, VdbeCursor *pCsr){
   VdbeSorter *pSorter = pCsr->pSorter;
   if( pSorter ){
-    if( pSorter->aIter ){
-      int i;
-      for(i=0; i<pSorter->nTree; i++){
-        vdbeSorterIterZero(db, &pSorter->aIter[i]);
-      }
-      sqlite3DbFree(db, pSorter->aIter);
-    }
-    if( pSorter->pTemp1 ){
-      sqlite3OsCloseFree(pSorter->pTemp1);
-    }
-    vdbeSorterRecordFree(db, pSorter->pRecord);
+    sqlite3VdbeSorterReset(db, pSorter);
     sqlite3DbFree(db, pSorter->pUnpacked);
     sqlite3DbFree(db, pSorter);
     pCsr->pSorter = 0;
   }
 }