SQLite

  Parse *pParse,       /* Parsing context */
  ExprList *pList,     /* Form the KeyInfo object from this ExprList */
  int iStart,          /* Begin with this column of pList */
  int nExtra           /* Add this many extra columns to the end */
);

/*
** Generate code that will push the record in registers regData
** through regData+nData-1 onto the sorter.
*/
static void pushOntoSorter(
  Parse *pParse,         /* Parser context */
  SortCtx *pSort,        /* Information about the ORDER BY clause */
  Select *pSelect,       /* The whole SELECT statement */
  int regData,           /* First register holding data to be sorted */
  int nData              /* Number of elements in the data array */
){
  Vdbe *v = pParse->pVdbe;                         /* Stmt under construction */
  int nExpr = pSort->pOrderBy->nExpr;              /* No. of ORDER BY terms */
  int nBase = nExpr + 1 + nData;                   /* Fields in sorter record */
  int regBase = sqlite3GetTempRange(pParse, nBase); /* Regs for sorter record */
  int regRecord = sqlite3GetTempReg(pParse);       /* Assemblied sorter record */
  int nOBSat = pSort->nOBSat;                      /* No. ORDER BY terms to skip */
  int op;                               /* Opcode to add sorter record to sorter */

  sqlite3ExprCacheClear(pParse);
  sqlite3ExprCodeExprList(pParse, pSort->pOrderBy, regBase, 0);
  sqlite3VdbeAddOp2(v, OP_Sequence, pSort->iECursor, regBase+nExpr);
  sqlite3VdbeAddOp3(v, OP_Move, regData, regBase+nExpr+1, nData);
  sqlite3VdbeAddOp3(v, OP_MakeRecord, regBase+nOBSat, nBase-nOBSat, regRecord);
  if( nOBSat>0 ){
    int regPrevKey;   /* The first nOBSat columns of the previous row */
    int addrFirst;    /* Address of the OP_IfNot opcode */
    int addrJmp;      /* Address of the OP_Jump opcode */
    VdbeOp *pOp;      /* Opcode that opens the sorter */
    int nKey;         /* Number of sorting key columns, including OP_Sequence */

    op = OP_SorterInsert;
  }else{
    op = OP_IdxInsert;
  }
  sqlite3VdbeAddOp2(v, op, pSort->iECursor, regRecord);
  if( nOBSat==0 ){
    sqlite3ReleaseTempReg(pParse, regRecord);
    sqlite3ReleaseTempRange(pParse, regBase, nBase);
  }
  if( pSelect->iLimit ){
    int addr1, addr2;
    int iLimit;
    if( pSelect->iOffset ){
      iLimit = pSelect->iOffset+1;
    }else{

        int addr = sqlite3VdbeCurrentAddr(v) + 4;
        sqlite3VdbeAddOp4Int(v, OP_Found, iParm+1, addr, r1, 0); VdbeCoverage(v);
        sqlite3VdbeAddOp2(v, OP_IdxInsert, iParm+1, r1);
        assert( pSort==0 );
      }
#endif
      if( pSort ){
        pushOntoSorter(pParse, pSort, p, r1, 1);
      }else{
        int r2 = sqlite3GetTempReg(pParse);
        sqlite3VdbeAddOp2(v, OP_NewRowid, iParm, r2);
        sqlite3VdbeAddOp3(v, OP_Insert, iParm, r1, r2);
        sqlite3VdbeChangeP5(v, OPFLAG_APPEND);
        sqlite3ReleaseTempReg(pParse, r2);
      }

      pDest->affSdst =
                  sqlite3CompareAffinity(pEList->a[0].pExpr, pDest->affSdst);
      if( pSort ){
        /* At first glance you would think we could optimize out the
        ** ORDER BY in this case since the order of entries in the set
        ** does not matter.  But there might be a LIMIT clause, in which
        ** case the order does matter */
        pushOntoSorter(pParse, pSort, p, regResult, 1);
      }else{
        int r1 = sqlite3GetTempReg(pParse);
        sqlite3VdbeAddOp4(v, OP_MakeRecord, regResult,1,r1, &pDest->affSdst, 1);
        sqlite3ExprCacheAffinityChange(pParse, regResult, 1);
        sqlite3VdbeAddOp2(v, OP_IdxInsert, iParm, r1);
        sqlite3ReleaseTempReg(pParse, r1);
      }

    /* If this is a scalar select that is part of an expression, then
    ** store the results in the appropriate memory cell and break out
    ** of the scan loop.
    */
    case SRT_Mem: {
      assert( nResultCol==1 );
      if( pSort ){
        pushOntoSorter(pParse, pSort, p, regResult, 1);
      }else{
        sqlite3ExprCodeMove(pParse, regResult, iParm, 1);
        /* The LIMIT clause will jump out of the loop for us */
      }
      break;
    }
#endif /* #ifndef SQLITE_OMIT_SUBQUERY */

    case SRT_Coroutine:       /* Send data to a co-routine */
    case SRT_Output: {        /* Return the results */
      testcase( eDest==SRT_Coroutine );
      testcase( eDest==SRT_Output );
      if( pSort ){


        pushOntoSorter(pParse, pSort, p, regResult, nResultCol);

      }else if( eDest==SRT_Coroutine ){
        sqlite3VdbeAddOp1(v, OP_Yield, pDest->iSDParm);
      }else{
        sqlite3VdbeAddOp2(v, OP_ResultRow, regResult, nResultCol);
        sqlite3ExprCacheAffinityChange(pParse, regResult, nResultCol);
      }
      break;

  int pseudoTab = 0;
  ExprList *pOrderBy = pSort->pOrderBy;
  int eDest = pDest->eDest;
  int iParm = pDest->iSDParm;
  int regRow;
  int regRowid;
  int nKey;
  int iSortTab;                   /* Sorter cursor to read from */
  int nSortData;                  /* Trailing values to read from sorter */
  u8 p5;                          /* p5 parameter for 1st OP_Column */
  int i;

  if( pSort->labelBkOut ){
    sqlite3VdbeAddOp2(v, OP_Gosub, pSort->regReturn, pSort->labelBkOut);
    sqlite3VdbeAddOp2(v, OP_Goto, 0, addrBreak);
    sqlite3VdbeResolveLabel(v, pSort->labelBkOut);
    addrOnce = sqlite3CodeOnce(pParse); VdbeCoverage(v);
  }
  iTab = pSort->iECursor;
  regRow = sqlite3GetTempReg(pParse);
  if( eDest==SRT_Output || eDest==SRT_Coroutine ){
    pseudoTab = pParse->nTab++;
    sqlite3VdbeAddOp3(v, OP_OpenPseudo, pseudoTab, regRow, nColumn);
    regRowid = 0;
    regRow = pDest->iSdst;
    nSortData = nColumn;
  }else{
    regRowid = sqlite3GetTempReg(pParse);
    regRow = sqlite3GetTempReg(pParse);
    nSortData = 1;
  }
  nKey = pOrderBy->nExpr - pSort->nOBSat;
  if( pSort->sortFlags & SORTFLAG_UseSorter ){
    int regSortOut = ++pParse->nMem;
    iSortTab = pParse->nTab++;
    sqlite3VdbeAddOp3(v, OP_OpenPseudo, iSortTab, regSortOut, nKey+1+nSortData);
    if( addrOnce ) sqlite3VdbeJumpHere(v, addrOnce);
    addr = 1 + sqlite3VdbeAddOp2(v, OP_SorterSort, iTab, addrBreak);
    VdbeCoverage(v);
    codeOffset(v, p->iOffset, addrContinue);
    sqlite3VdbeAddOp2(v, OP_SorterData, iTab, regSortOut);

    p5 = OPFLAG_CLEARCACHE;
  }else{
    if( addrOnce ) sqlite3VdbeJumpHere(v, addrOnce);
    addr = 1 + sqlite3VdbeAddOp2(v, OP_Sort, iTab, addrBreak); VdbeCoverage(v);
    codeOffset(v, p->iOffset, addrContinue);
    sqlite3VdbeAddOp3(v, OP_Column, iTab, nKey+1, regRow);
    iSortTab = iTab;
    p5 = 0;
  }
  for(i=0; i<nSortData; i++){
    sqlite3VdbeAddOp3(v, OP_Column, iSortTab, nKey+1+i, regRow+i);
    if( i==0 ) sqlite3VdbeChangeP5(v, p5);
  }
  switch( eDest ){
    case SRT_Table:
    case SRT_EphemTab: {
      testcase( eDest==SRT_Table );
      testcase( eDest==SRT_EphemTab );
      sqlite3VdbeAddOp2(v, OP_NewRowid, iParm, regRowid);

      assert( nColumn==1 );
      sqlite3ExprCodeMove(pParse, regRow, iParm, 1);
      /* The LIMIT clause will terminate the loop for us */
      break;
    }
#endif
    default: {

      assert( eDest==SRT_Output || eDest==SRT_Coroutine ); 
      testcase( eDest==SRT_Output );
      testcase( eDest==SRT_Coroutine );







      if( eDest==SRT_Output ){
        sqlite3VdbeAddOp2(v, OP_ResultRow, pDest->iSdst, nColumn);
        sqlite3ExprCacheAffinityChange(pParse, pDest->iSdst, nColumn);
      }else{
        sqlite3VdbeAddOp1(v, OP_Yield, pDest->iSDParm);
      }
      break;
    }
  }
  if( regRowid ){
    sqlite3ReleaseTempReg(pParse, regRow);
    sqlite3ReleaseTempReg(pParse, regRowid);
  }
  /* The bottom of the loop
  */
  sqlite3VdbeResolveLabel(v, addrContinue);
  if( pSort->sortFlags & SORTFLAG_UseSorter ){
    sqlite3VdbeAddOp2(v, OP_SorterNext, iTab, addr); VdbeCoverage(v);
  }else{
    sqlite3VdbeAddOp2(v, OP_Next, iTab, addr); VdbeCoverage(v);
  }
  if( pSort->regReturn ) sqlite3VdbeAddOp1(v, OP_Return, pSort->regReturn);
  sqlite3VdbeResolveLabel(v, addrBreak);



}

/*
** Return a pointer to a string containing the 'declaration type' of the
** expression pExpr. The string may be treated as static by the caller.
**
** Also try to estimate the size of the returned value and return that

  */
  if( sSort.pOrderBy ){
    KeyInfo *pKeyInfo;
    pKeyInfo = keyInfoFromExprList(pParse, sSort.pOrderBy, 0, 0);
    sSort.iECursor = pParse->nTab++;
    sSort.addrSortIndex =
      sqlite3VdbeAddOp4(v, OP_OpenEphemeral,
          sSort.iECursor, sSort.pOrderBy->nExpr+1+pEList->nExpr, 0,
          (char*)pKeyInfo, P4_KEYINFO
      );
  }else{
    sSort.addrSortIndex = -1;
  }

  /* If the output is destined for a temporary table, open that table.
  */
  if( pDest->eDest==SRT_EphemTab ){

    set G ""
    set B ""
    set D ""
  }
  foreach opcode {
      Seek SeekGe SeekGt SeekLe SeekLt NotFound Last Rewind
      NoConflict Next Prev VNext VPrev VFilter
      SorterSort SorterNext
  } {
    set color($opcode) $B
  }
  foreach opcode {ResultRow} {
    set color($opcode) $G
  }
  foreach opcode {IdxInsert Insert Delete IdxDelete} {

    if {$opcode == "Goto" && ($bSeenGoto==0 || ($p2 > $addr+10))} {
      set linebreak($p2) 1
      set bSeenGoto 1
    }

    if {$opcode=="Next"  || $opcode=="Prev" 
     || $opcode=="VNext" || $opcode=="VPrev"
     || $opcode=="SorterNext"
    } {
      for {set i $p2} {$i<$addr} {incr i} {
        incr x($i) 2
      }
    }

    if {$opcode == "Goto" && $p2<$addr && $op($p2)=="Yield"} {