Avoid storing redundant fields in sorter records when the sort-key and data have

fields in common (as in "SELECT a FROM t1 ORDER BY 1").

FossilOrigin-Name: 0af62fdbd8e2aab14718ff8bcb5934f05463c176

manifest

@@ -1,5 +1,5 @@
-C Fix\stypo\sin\sthe\sCSV\sextension.
-D 2016-11-09T01:46:13.326
+C Avoid\sstoring\sredundant\sfields\sin\ssorter\srecords\swhen\sthe\ssort-key\sand\sdata\shave\nfields\sin\scommon\s(as\sin\s"SELECT\sa\sFROM\st1\sORDER\sBY\s1").
+D 2016-11-10T20:14:06.787
 F Makefile.in 6fd48ffcf7c2deea7499062d1f3747f986c19678
 F Makefile.linux-gcc 7bc79876b875010e8c8f9502eb935ca92aa3c434
 F Makefile.msc e0217f2d35a0448abbe4b066132ae20136e8b408
@@ -340,7 +340,7 @@ F src/ctime.c a2a52d6e353f459d8ab0f07321f60fafa47d5421
 F src/date.c 95c9a8d00767e7221a8e9a31f4e913fc8029bf6b
 F src/dbstat.c 19ee7a4e89979d4df8e44cfac7a8f905ec89b77d
 F src/delete.c cb3f6300df24c26c609778b2731f82644b5532ec
-F src/expr.c ce7110980fac6dfdfbe1e393443bdb79bad29339
+F src/expr.c 1fd53148e575de810ad10a9eb15f16f2e44ff1dc
 F src/fault.c 160a0c015b6c2629d3899ed2daf63d75754a32bb
 F src/fkey.c b9ca262f6ad4d030a3cab737ebf9b0b3c8b4ac80
 F src/func.c 7057bc2c105b82faa668d8e2ec85fad4540e5c51
@@ -387,12 +387,12 @@ F src/printf.c a5f0ca08ddede803c241266abb46356ec748ded1
 F src/random.c ba2679f80ec82c4190062d756f22d0c358180696
 F src/resolve.c 3fac1b2737ea5a724f20b921ac7e259c9be2100b
 F src/rowset.c 7b7e7e479212e65b723bf40128c7b36dc5afdfac
-F src/select.c ea3af83e2d0f245fef81ea4cf04cb730ce67f722
+F src/select.c 64b2273747c6485638bfeb6790e3e774e0605d02
 F src/shell.c 63e54cfa1c7ec5b70a4c9a86502bc10280c3d5a3
 F src/sqlite.h.in 803f7050f69b2eea573fac219f3c92582c096027
 F src/sqlite3.rc 5121c9e10c3964d5755191c80dd1180c122fc3a8
 F src/sqlite3ext.h 8648034aa702469afb553231677306cc6492a1ae
-F src/sqliteInt.h 37628fe30c464dc790bcee3bfd3d0caa8f222ed1
+F src/sqliteInt.h 603953faca895386d4f3a8b7046f3e4e6c071c53
 F src/sqliteLimit.h c0373387c287c8d0932510b5547ecde31b5da247
 F src/status.c a9e66593dfb28a9e746cba7153f84d49c1ddc4b1
 F src/table.c 5226df15ab9179b9ed558d89575ea0ce37b03fc9
@@ -1530,7 +1530,10 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P 754ee844958bdc3b96acfd1f5395da5796e54a82
-R eb905f0421ecb200099f22c1d4910f11
-U mistachkin
-Z a09941219c710c6bfaf84cdaf6c10994
+P b4889588246c33374ff3758e21ccc4ce246380b6
+R e8a5368c67459f65dc206ad3df15a284
+T *branch * sorter-opt
+T *sym-sorter-opt *
+T -sym-trunk *
+U dan
+Z 220ba0a8da96dcdf18555b62136e6fa1

manifest.uuid

@@ -1 +1 @@
-b4889588246c33374ff3758e21ccc4ce246380b6
+0af62fdbd8e2aab14718ff8bcb5934f05463c176

src/expr.c

@@ -4086,8 +4086,13 @@ int sqlite3ExprCodeExprList(
   if( !ConstFactorOk(pParse) ) flags &= ~SQLITE_ECEL_FACTOR;
   for(pItem=pList->a, i=0; i<n; i++, pItem++){
     Expr *pExpr = pItem->pExpr;
-    if( (flags & SQLITE_ECEL_REF)!=0 && (j = pList->a[i].u.x.iOrderByCol)>0 ){
-      sqlite3VdbeAddOp2(v, copyOp, j+srcReg-1, target+i);
+    if( (flags & SQLITE_ECEL_REF)!=0 && (j = pItem->u.x.iOrderByCol)>0 ){
+      if( flags & SQLITE_ECEL_OMITREF ){
+        i--;
+        n--;
+      }else{
+        sqlite3VdbeAddOp2(v, copyOp, j+srcReg-1, target+i);
+      }
     }else if( (flags & SQLITE_ECEL_FACTOR)!=0 && sqlite3ExprIsConstant(pExpr) ){
       sqlite3ExprCodeAtInit(pParse, pExpr, target+i, 0);
     }else{

src/select.c

@@ -533,11 +533,11 @@ static void pushOntoSorter(
   iLimit = pSelect->iOffset ? pSelect->iOffset+1 : pSelect->iLimit;
   pSort->labelDone = sqlite3VdbeMakeLabel(v);
   sqlite3ExprCodeExprList(pParse, pSort->pOrderBy, regBase, regOrigData,
-                          SQLITE_ECEL_DUP|SQLITE_ECEL_REF);
+                          SQLITE_ECEL_DUP);
   if( bSeq ){
     sqlite3VdbeAddOp2(v, OP_Sequence, pSort->iECursor, regBase+nExpr);
   }
-  if( nPrefixReg==0 ){
+  if( nPrefixReg==0 && nData>0 ){
     sqlite3ExprCodeMove(pParse, regData, regBase+nExpr+bSeq, nData);
   }
   sqlite3VdbeAddOp3(v, OP_MakeRecord, regBase+nOBSat, nBase-nOBSat, regRecord);
@@ -666,7 +666,7 @@ static void codeDistinct(
 ** If srcTab is negative, then the pEList expressions
 ** are evaluated in order to get the data for this row.  If srcTab is
 ** zero or more, then data is pulled from srcTab and pEList is used only 
-** to get number columns and the datatype for each column.
+** to get the number of columns and the collation sequence for each column.
 */
 static void selectInnerLoop(
   Parse *pParse,          /* The parser context */
@@ -734,7 +734,25 @@ static void selectInnerLoop(
     }else{
       ecelFlags = 0;
     }
-    sqlite3ExprCodeExprList(pParse, pEList, regResult, 0, ecelFlags);
+    if( pSort && hasDistinct==0 && eDest!=SRT_EphemTab && eDest!=SRT_Table ){
+      /* For each expression in pEList that is a copy of an expression in
+      ** the ORDER BY clause (pSort->pOrderBy), set the associated 
+      ** iOrderByCol value to one more than the index of the ORDER BY 
+      ** expression within the sort-key that pushOntoSorter() will generate.
+      ** This allows the pEList field to be omitted from the sorted record,
+      ** saving space and CPU cycles.  */
+      ecelFlags |= (SQLITE_ECEL_OMITREF|SQLITE_ECEL_REF);
+      for(i=pSort->nOBSat; i<pSort->pOrderBy->nExpr; i++){
+        int j;
+        if( (j = pSort->pOrderBy->a[i].u.x.iOrderByCol)>0 ){
+          pEList->a[j-1].u.x.iOrderByCol = i+1-pSort->nOBSat;
+        }
+      }
+
+      assert( eDest==SRT_Set || eDest==SRT_Mem 
+           || eDest==SRT_Coroutine || eDest==SRT_Output );
+    }
+    nResultCol = sqlite3ExprCodeExprList(pParse,pEList,regResult,0,ecelFlags);
   }
 
   /* If the DISTINCT keyword was present on the SELECT statement
@@ -900,11 +918,12 @@ static void selectInnerLoop(
     ** memory cells and break out of the scan loop.
     */
     case SRT_Mem: {
-      assert( nResultCol==pDest->nSdst );
       if( pSort ){
+        assert( nResultCol<=pDest->nSdst );
         pushOntoSorter(
             pParse, pSort, p, regResult, regResult, nResultCol, nPrefixReg);
       }else{
+        assert( nResultCol==pDest->nSdst );
         assert( regResult==iParm );
         /* The LIMIT clause will jump out of the loop for us */
       }
@@ -1202,14 +1221,13 @@ static void generateSortTail(
   int iParm = pDest->iSDParm;
   int regRow;
   int regRowid;
+  int iCol;
   int nKey;
   int iSortTab;                   /* Sorter cursor to read from */
   int nSortData;                  /* Trailing values to read from sorter */
   int i;
   int bSeq;                       /* True if sorter record includes seq. no. */
-#ifdef SQLITE_ENABLE_EXPLAIN_COMMENTS
   struct ExprList_item *aOutEx = p->pEList->a;
-#endif
 
   assert( addrBreak<0 );
   if( pSort->labelBkOut ){
@@ -1247,8 +1265,14 @@ static void generateSortTail(
     iSortTab = iTab;
     bSeq = 1;
   }
-  for(i=0; i<nSortData; i++){
-    sqlite3VdbeAddOp3(v, OP_Column, iSortTab, nKey+bSeq+i, regRow+i);
+  for(i=0, iCol=nKey+bSeq; i<nSortData; i++){
+    int iRead;
+    if( aOutEx[i].u.x.iOrderByCol ){
+      iRead = aOutEx[i].u.x.iOrderByCol-1;
+    }else{
+      iRead = iCol++;
+    }
+    sqlite3VdbeAddOp3(v, OP_Column, iSortTab, iRead, regRow+i);
     VdbeComment((v, "%s", aOutEx[i].zName ? aOutEx[i].zName : aOutEx[i].zSpan));
   }
   switch( eDest ){

src/sqliteInt.h

@@ -3706,6 +3706,7 @@ int sqlite3ExprCodeExprList(Parse*, ExprList*, int, int, u8);
 #define SQLITE_ECEL_DUP      0x01  /* Deep, not shallow copies */
 #define SQLITE_ECEL_FACTOR   0x02  /* Factor out constant terms */
 #define SQLITE_ECEL_REF      0x04  /* Use ExprList.u.x.iOrderByCol */
+#define SQLITE_ECEL_OMITREF  0x08  /* Omit if ExprList.u.x.iOrderByCol */
 void sqlite3ExprIfTrue(Parse*, Expr*, int, int);
 void sqlite3ExprIfFalse(Parse*, Expr*, int, int);
 void sqlite3ExprIfFalseDup(Parse*, Expr*, int, int);