Index: src/expr.c
==================================================================
--- src/expr.c
+++ src/expr.c
@@ -899,11 +899,12 @@
     pNewItem->zDatabase = sqlite3DbStrDup(db, pOldItem->zDatabase);
     pNewItem->zName = sqlite3DbStrDup(db, pOldItem->zName);
     pNewItem->zAlias = sqlite3DbStrDup(db, pOldItem->zAlias);
     pNewItem->jointype = pOldItem->jointype;
     pNewItem->iCursor = pOldItem->iCursor;
-    pNewItem->isPopulated = pOldItem->isPopulated;
+    pNewItem->addrFillSub = pOldItem->addrFillSub;
+    pNewItem->regReturn = pOldItem->regReturn;
     pNewItem->isCorrelated = pOldItem->isCorrelated;
     pNewItem->zIndex = sqlite3DbStrDup(db, pOldItem->zIndex);
     pNewItem->notIndexed = pOldItem->notIndexed;
     pNewItem->pIndex = pOldItem->pIndex;
     pTab = pNewItem->pTab = pOldItem->pTab;

Index: src/select.c
==================================================================
--- src/select.c
+++ src/select.c
@@ -3799,11 +3799,15 @@
     struct SrcList_item *pItem = &pTabList->a[i];
     SelectDest dest;
     Select *pSub = pItem->pSelect;
     int isAggSub;
 
-    if( pSub==0 || pItem->isPopulated ) continue;
+    if( pSub==0 ) continue;
+    if( pItem->addrFillSub ){
+      sqlite3VdbeAddOp2(v, OP_Gosub, pItem->regReturn, pItem->addrFillSub);
+      continue;
+    }
 
     /* Increment Parse.nHeight by the height of the largest expression
     ** tree refered to by this, the parent select. The child select
     ** may contain expression trees of at most
     ** (SQLITE_MAX_EXPR_DEPTH-Parse.nHeight) height. This is a bit
@@ -3810,25 +3814,45 @@
     ** more conservative than necessary, but much easier than enforcing
     ** an exact limit.
     */
     pParse->nHeight += sqlite3SelectExprHeight(p);
 
-    /* Check to see if the subquery can be absorbed into the parent. */
     isAggSub = (pSub->selFlags & SF_Aggregate)!=0;
     if( flattenSubquery(pParse, p, i, isAgg, isAggSub) ){
+      /* This subquery can be absorbed into its parent. */
       if( isAggSub ){
         isAgg = 1;
         p->selFlags |= SF_Aggregate;
       }
       i = -1;
     }else{
+      /* Generate a subroutine that will fill an ephemeral table with
+      ** the content of this subquery.  pItem->addrFillSub will point
+      ** to the address of the generated subroutine.  pItem->regReturn
+      ** is a register allocated to hold the subroutine return address
+      */
+      int topAddr = sqlite3VdbeAddOp0(v, OP_Goto);
+      int regOnce = 0;
+      assert( pItem->addrFillSub==0 );
+      pItem->addrFillSub = topAddr+1;
+      pItem->regReturn = ++pParse->nMem;
+      if( pItem->isCorrelated==0 && pParse->pTriggerTab==0 ){
+        /* If the subquery is no correlated and if we are not inside of
+        ** a trigger, then we only need to compute the value of the subquery
+        ** once. */
+        regOnce = ++pParse->nMem;
+        sqlite3VdbeAddOp1(v, OP_If, regOnce);
+        sqlite3VdbeAddOp2(v, OP_Integer, 1, regOnce);
+      }
       sqlite3SelectDestInit(&dest, SRT_EphemTab, pItem->iCursor);
-      assert( pItem->isPopulated==0 );
       explainSetInteger(pItem->iSelectId, (u8)pParse->iNextSelectId);
       sqlite3Select(pParse, pSub, &dest);
-      pItem->isPopulated = 1;
       pItem->pTab->nRowEst = (unsigned)pSub->nSelectRow;
+      if( regOnce ) sqlite3VdbeJumpHere(v, topAddr+1);
+      sqlite3VdbeAddOp1(v, OP_Return, pItem->regReturn);
+      sqlite3VdbeJumpHere(v, topAddr);
+      sqlite3VdbeAddOp2(v, OP_Gosub, pItem->regReturn, topAddr+1);
     }
     if( /*pParse->nErr ||*/ db->mallocFailed ){
       goto select_end;
     }
     pParse->nHeight -= sqlite3SelectExprHeight(p);

Index: src/sqliteInt.h
==================================================================
--- src/sqliteInt.h
+++ src/sqliteInt.h
@@ -1850,11 +1850,12 @@
     char *zDatabase;  /* Name of database holding this table */
     char *zName;      /* Name of the table */
     char *zAlias;     /* The "B" part of a "A AS B" phrase.  zName is the "A" */
     Table *pTab;      /* An SQL table corresponding to zName */
     Select *pSelect;  /* A SELECT statement used in place of a table name */
-    u8 isPopulated;   /* Temporary table associated with SELECT is populated */
+    int addrFillSub;  /* Address of subroutine to manifest a subquery */
+    int regReturn;    /* Register holding return address of addrFillSub */
     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 */