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Comment:Identify specific FuncDef objects for window functions using the pointer to the function name (FuncDef.zName) rather than the pointer to the xStep method. This allows xStep method pointer to be replaced with a single noopStepFunc() procedure, and thus save having lots of different no-op step functions.
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SHA3-256:410e13b0e0fb6e040808f076014d55ecf2b541c5439b4fd53c5bdcb8d800098e
User & Date: drh 2018-07-08 01:02:26
Context
2018-07-09
02:02
During WITHOUT ROWID table creation, if the sqlite3CreateTable() call fails due to an authorizer denying the INSERT into the sqlite_master table, then detect this fact and abort the CREATE TABLE early, to avoid an assertion fault. check-in: 164b1641 user: drh tags: trunk
2018-07-08
01:02
Identify specific FuncDef objects for window functions using the pointer to the function name (FuncDef.zName) rather than the pointer to the xStep method. This allows xStep method pointer to be replaced with a single noopStepFunc() procedure, and thus save having lots of different no-op step functions. check-in: 410e13b0 user: drh tags: trunk
2018-07-07
20:55
Simplifications to the implementation of the sum() SQL function. check-in: a8b13002 user: drh tags: trunk
Changes
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Changes to src/window.c.

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  sqlite3_context *pCtx, 
  int nArg,
  sqlite3_value **apArg
){
  i64 *p = (i64*)sqlite3_aggregate_context(pCtx, sizeof(*p));
  if( p ) (*p)++;
}
static void row_numberInvFunc(
  sqlite3_context *pCtx, 
  int nArg,
  sqlite3_value **apArg
){
}
static void row_numberValueFunc(sqlite3_context *pCtx){
  i64 *p = (i64*)sqlite3_aggregate_context(pCtx, sizeof(*p));
  sqlite3_result_int64(pCtx, (p ? *p : 0));
}

/*
** Context object type used by rank(), dense_rank(), percent_rank() and
................................................................................
  int nArg,
  sqlite3_value **apArg
){
  struct CallCount *p;
  p = (struct CallCount*)sqlite3_aggregate_context(pCtx, sizeof(*p));
  if( p ) p->nStep = 1;
}
static void dense_rankInvFunc(
  sqlite3_context *pCtx, 
  int nArg,
  sqlite3_value **apArg
){
}
static void dense_rankValueFunc(sqlite3_context *pCtx){
  struct CallCount *p;
  p = (struct CallCount*)sqlite3_aggregate_context(pCtx, sizeof(*p));
  if( p ){
    if( p->nStep ){
      p->nValue++;
      p->nStep = 0;
................................................................................
  if( p ){
    p->nStep++;
    if( p->nValue==0 ){
      p->nValue = p->nStep;
    }
  }
}
static void rankInvFunc(
  sqlite3_context *pCtx, 
  int nArg,
  sqlite3_value **apArg
){
}
static void rankValueFunc(sqlite3_context *pCtx){
  struct CallCount *p;
  p = (struct CallCount*)sqlite3_aggregate_context(pCtx, sizeof(*p));
  if( p ){
    sqlite3_result_int64(pCtx, p->nValue);
    p->nValue = 0;
  }
................................................................................
    }
    p->nStep++;
    if( p->nValue==0 ){
      p->nValue = p->nStep;
    }
  }
}
static void percent_rankInvFunc(
  sqlite3_context *pCtx, 
  int nArg,
  sqlite3_value **apArg
){
}
static void percent_rankValueFunc(sqlite3_context *pCtx){
  struct CallCount *p;
  p = (struct CallCount*)sqlite3_aggregate_context(pCtx, sizeof(*p));
  if( p ){
    if( p->nTotal>1 ){
      double r = (double)(p->nValue-1) / (double)(p->nTotal-1);
      sqlite3_result_double(pCtx, r);
................................................................................
  if( p ){
    if( p->nTotal==0 ){
      p->nTotal = sqlite3_value_int64(apArg[0]);
    }
    p->nStep++;
  }
}
static void cume_distInvFunc(
  sqlite3_context *pCtx, 
  int nArg,
  sqlite3_value **apArg
){
}
static void cume_distValueFunc(sqlite3_context *pCtx){
  struct CallCount *p;
  p = (struct CallCount*)sqlite3_aggregate_context(pCtx, sizeof(*p));
  if( p && p->nTotal ){
    double r = (double)(p->nStep) / (double)(p->nTotal);
    sqlite3_result_double(pCtx, r);
  }
................................................................................
            pCtx, "argument of ntile must be a positive integer", -1
        );
      }
    }
    p->iRow++;
  }
}
static void ntileInvFunc(
  sqlite3_context *pCtx, 
  int nArg,
  sqlite3_value **apArg
){
}
static void ntileValueFunc(sqlite3_context *pCtx){
  struct NtileCtx *p;
  p = (struct NtileCtx*)sqlite3_aggregate_context(pCtx, sizeof(*p));
  if( p && p->nParam>0 ){
    int nSize = (p->nTotal / p->nParam);
    if( nSize==0 ){
      sqlite3_result_int64(pCtx, p->iRow);
................................................................................
    sqlite3_result_value(pCtx, p->pVal);
    sqlite3_value_free(p->pVal);
    p->pVal = 0;
  }
}

/*
** No-op implementations of nth_value(), first_value(), lead() and lag().
** These are all implemented inline using VDBE instructions. 




*/
static void nth_valueStepFunc(sqlite3_context *pCtx, int n, sqlite3_value **a){}
static void nth_valueInvFunc(sqlite3_context *pCtx, int n, sqlite3_value **ap){}
static void nth_valueValueFunc(sqlite3_context *pCtx){}
static void first_valueStepFunc(sqlite3_context *p, int n, sqlite3_value **ap){}
static void first_valueInvFunc(sqlite3_context *p, int n, sqlite3_value **ap){}
static void first_valueValueFunc(sqlite3_context *pCtx){}
static void leadStepFunc(sqlite3_context *pCtx, int n, sqlite3_value **ap){}
static void leadInvFunc(sqlite3_context *pCtx, int n, sqlite3_value **ap){}


















static void leadValueFunc(sqlite3_context *pCtx){}
static void lagStepFunc(sqlite3_context *pCtx, int n, sqlite3_value **ap){}
static void lagInvFunc(sqlite3_context *pCtx, int n, sqlite3_value **ap){}





static void lagValueFunc(sqlite3_context *pCtx){}



#define WINDOWFUNC(name,nArg,extra) {                                      \
  nArg, (SQLITE_UTF8|SQLITE_FUNC_WINDOW|extra), 0, 0,                      \
  name ## StepFunc, name ## ValueFunc, name ## ValueFunc,                  \
  name ## InvFunc, #name                                               \


}












#define WINDOWFUNCF(name,nArg,extra) {                                     \
  nArg, (SQLITE_UTF8|SQLITE_FUNC_WINDOW|extra), 0, 0,                      \
  name ## StepFunc, name ## FinalizeFunc, name ## ValueFunc,               \
  name ## InvFunc, #name                                               \


}


/*
** Register those built-in window functions that are not also aggregates.
*/
void sqlite3WindowFunctions(void){
  static FuncDef aWindowFuncs[] = {
    WINDOWFUNC(row_number, 0, 0),
    WINDOWFUNC(dense_rank, 0, 0),
    WINDOWFUNC(rank, 0, 0),
    WINDOWFUNC(percent_rank, 0, SQLITE_FUNC_WINDOW_SIZE),
    WINDOWFUNC(cume_dist, 0, SQLITE_FUNC_WINDOW_SIZE),
    WINDOWFUNC(ntile, 1, SQLITE_FUNC_WINDOW_SIZE),
    WINDOWFUNCF(last_value, 1, 0),
    WINDOWFUNC(nth_value, 2, 0),
    WINDOWFUNC(first_value, 1, 0),
    WINDOWFUNC(lead, 1, 0), WINDOWFUNC(lead, 2, 0), WINDOWFUNC(lead, 3, 0),
    WINDOWFUNC(lag, 1, 0),  WINDOWFUNC(lag, 2, 0),  WINDOWFUNC(lag, 3, 0),




  };
  sqlite3InsertBuiltinFuncs(aWindowFuncs, ArraySize(aWindowFuncs));
}

/*
** This function is called immediately after resolving the function name
** for a window function within a SELECT statement. Argument pList is a
................................................................................
  if( pFunc->funcFlags & SQLITE_FUNC_WINDOW ){
    sqlite3 *db = pParse->db;
    if( pWin->pFilter ){
      sqlite3ErrorMsg(pParse, 
          "FILTER clause may only be used with aggregate window functions"
      );
    }else
    if( pFunc->xSFunc==row_numberStepFunc || pFunc->xSFunc==ntileStepFunc ){
      sqlite3ExprDelete(db, pWin->pStart);
      sqlite3ExprDelete(db, pWin->pEnd);
      pWin->pStart = pWin->pEnd = 0;
      pWin->eType = TK_ROWS;
      pWin->eStart = TK_UNBOUNDED;
      pWin->eEnd = TK_CURRENT;
    }else

    if( pFunc->xSFunc==dense_rankStepFunc || pFunc->xSFunc==rankStepFunc
     || pFunc->xSFunc==percent_rankStepFunc || pFunc->xSFunc==cume_distStepFunc
    ){
      sqlite3ExprDelete(db, pWin->pStart);
      sqlite3ExprDelete(db, pWin->pEnd);
      pWin->pStart = pWin->pEnd = 0;
      pWin->eType = TK_RANGE;
      pWin->eStart = TK_UNBOUNDED;
      pWin->eEnd = TK_CURRENT;
................................................................................
        assert( pKeyInfo->aSortOrder[0]==0 );
        pKeyInfo->aSortOrder[0] = 1;
      }
      sqlite3VdbeAddOp2(v, OP_OpenEphemeral, pWin->csrApp, 2);
      sqlite3VdbeAppendP4(v, pKeyInfo, P4_KEYINFO);
      sqlite3VdbeAddOp2(v, OP_Integer, 0, pWin->regApp+1);
    }
    else if( p->xSFunc==nth_valueStepFunc || p->xSFunc==first_valueStepFunc ){
      /* Allocate two registers at pWin->regApp. These will be used to
      ** store the start and end index of the current frame.  */
      assert( pMWin->iEphCsr );
      pWin->regApp = pParse->nMem+1;
      pWin->csrApp = pParse->nTab++;
      pParse->nMem += 2;
      sqlite3VdbeAddOp2(v, OP_OpenDup, pWin->csrApp, pMWin->iEphCsr);
    }
    else if( p->xSFunc==leadStepFunc || p->xSFunc==lagStepFunc ){
      assert( pMWin->iEphCsr );
      pWin->csrApp = pParse->nTab++;
      sqlite3VdbeAddOp2(v, OP_OpenDup, pWin->csrApp, pMWin->iEphCsr);
    }
  }
}

................................................................................
        sqlite3VdbeAddOp4Int(v, OP_SeekGE, pWin->csrApp, 0, regArg, 1);
        VdbeCoverage(v);
        sqlite3VdbeAddOp1(v, OP_Delete, pWin->csrApp);
        sqlite3VdbeJumpHere(v, sqlite3VdbeCurrentAddr(v)-2);
      }
      sqlite3VdbeJumpHere(v, addrIsNull);
    }else if( pWin->regApp ){
      assert( pWin->pFunc->xSFunc==nth_valueStepFunc 
           || pWin->pFunc->xSFunc==first_valueStepFunc 
      );
      assert( bInverse==0 || bInverse==1 );
      sqlite3VdbeAddOp2(v, OP_AddImm, pWin->regApp+1-bInverse, 1);
    }else if( pWin->pFunc->xSFunc==leadStepFunc 
           || pWin->pFunc->xSFunc==lagStepFunc 
    ){
      /* no-op */
    }else{
      int addrIf = 0;
      if( pWin->pFilter ){
        int regTmp;
        assert( nArg==pWin->pOwner->x.pList->nExpr );
................................................................................
  int regGosub,
  int addrGosub
){
  Vdbe *v = sqlite3GetVdbe(pParse);
  Window *pWin;
  for(pWin=pMWin; pWin; pWin=pWin->pNextWin){
    FuncDef *pFunc = pWin->pFunc;
    if( pFunc->xSFunc==nth_valueStepFunc 
     || pFunc->xSFunc==first_valueStepFunc 
    ){
      int csr = pWin->csrApp;
      int lbl = sqlite3VdbeMakeLabel(v);
      int tmpReg = sqlite3GetTempReg(pParse);
      sqlite3VdbeAddOp2(v, OP_Null, 0, pWin->regResult);

      if( pFunc->xSFunc==nth_valueStepFunc ){
        sqlite3VdbeAddOp3(v, OP_Column, pMWin->iEphCsr, pWin->iArgCol+1,tmpReg);
      }else{
        sqlite3VdbeAddOp2(v, OP_Integer, 1, tmpReg);
      }
      sqlite3VdbeAddOp3(v, OP_Add, tmpReg, pWin->regApp, tmpReg);
      sqlite3VdbeAddOp3(v, OP_Gt, pWin->regApp+1, lbl, tmpReg);
      VdbeCoverage(v);
      sqlite3VdbeAddOp3(v, OP_SeekRowid, csr, lbl, tmpReg);
      VdbeCoverage(v);
      sqlite3VdbeAddOp3(v, OP_Column, csr, pWin->iArgCol, pWin->regResult);
      sqlite3VdbeResolveLabel(v, lbl);
      sqlite3ReleaseTempReg(pParse, tmpReg);
    }
    else if( pFunc->xSFunc==leadStepFunc || pFunc->xSFunc==lagStepFunc ){
      int nArg = pWin->pOwner->x.pList->nExpr;
      int iEph = pMWin->iEphCsr;
      int csr = pWin->csrApp;
      int lbl = sqlite3VdbeMakeLabel(v);
      int tmpReg = sqlite3GetTempReg(pParse);

      if( nArg<3 ){
        sqlite3VdbeAddOp2(v, OP_Null, 0, pWin->regResult);
      }else{
        sqlite3VdbeAddOp3(v, OP_Column, iEph, pWin->iArgCol+2, pWin->regResult);
      }
      sqlite3VdbeAddOp2(v, OP_Rowid, iEph, tmpReg);
      if( nArg<2 ){
        int val = (pFunc->xSFunc==leadStepFunc ? 1 : -1);
        sqlite3VdbeAddOp2(v, OP_AddImm, tmpReg, val);
      }else{
        int op = (pFunc->xSFunc==leadStepFunc ? OP_Add : OP_Subtract);
        int tmpReg2 = sqlite3GetTempReg(pParse);
        sqlite3VdbeAddOp3(v, OP_Column, iEph, pWin->iArgCol+1, tmpReg2);
        sqlite3VdbeAddOp3(v, op, tmpReg2, tmpReg, tmpReg);
        sqlite3ReleaseTempReg(pParse, tmpReg2);
      }

      sqlite3VdbeAddOp3(v, OP_SeekRowid, csr, lbl, tmpReg);
................................................................................
  int regArg;
  int nArg = 0;
  Window *pWin;
  for(pWin=pMWin; pWin; pWin=pWin->pNextWin){
    FuncDef *pFunc = pWin->pFunc;
    sqlite3VdbeAddOp2(v, OP_Null, 0, pWin->regAccum);
    nArg = MAX(nArg, windowArgCount(pWin));
    if( pFunc->xSFunc==nth_valueStepFunc
     || pFunc->xSFunc==first_valueStepFunc 
    ){
      sqlite3VdbeAddOp2(v, OP_Integer, 0, pWin->regApp);
      sqlite3VdbeAddOp2(v, OP_Integer, 0, pWin->regApp+1);
    }

    if( (pFunc->funcFlags & SQLITE_FUNC_MINMAX) && pWin->csrApp ){
      assert( pWin->eStart!=TK_UNBOUNDED );
................................................................................

    if( pMWin->eStart==TK_CURRENT && pMWin->eEnd==TK_UNBOUNDED ){
      bCache = 1;
    }else{
      for(pWin=pMWin; pWin; pWin=pWin->pNextWin){
        FuncDef *pFunc = pWin->pFunc;
        if( (pFunc->funcFlags & SQLITE_FUNC_WINDOW_SIZE)
         || (pFunc->xSFunc==nth_valueStepFunc)
         || (pFunc->xSFunc==first_valueStepFunc)
         || (pFunc->xSFunc==leadStepFunc)
         || (pFunc->xSFunc==lagStepFunc)
        ){
          bCache = 1;
          break;
        }
      }
    }








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  sqlite3_context *pCtx, 
  int nArg,
  sqlite3_value **apArg
){
  i64 *p = (i64*)sqlite3_aggregate_context(pCtx, sizeof(*p));
  if( p ) (*p)++;
}






static void row_numberValueFunc(sqlite3_context *pCtx){
  i64 *p = (i64*)sqlite3_aggregate_context(pCtx, sizeof(*p));
  sqlite3_result_int64(pCtx, (p ? *p : 0));
}

/*
** Context object type used by rank(), dense_rank(), percent_rank() and
................................................................................
  int nArg,
  sqlite3_value **apArg
){
  struct CallCount *p;
  p = (struct CallCount*)sqlite3_aggregate_context(pCtx, sizeof(*p));
  if( p ) p->nStep = 1;
}






static void dense_rankValueFunc(sqlite3_context *pCtx){
  struct CallCount *p;
  p = (struct CallCount*)sqlite3_aggregate_context(pCtx, sizeof(*p));
  if( p ){
    if( p->nStep ){
      p->nValue++;
      p->nStep = 0;
................................................................................
  if( p ){
    p->nStep++;
    if( p->nValue==0 ){
      p->nValue = p->nStep;
    }
  }
}






static void rankValueFunc(sqlite3_context *pCtx){
  struct CallCount *p;
  p = (struct CallCount*)sqlite3_aggregate_context(pCtx, sizeof(*p));
  if( p ){
    sqlite3_result_int64(pCtx, p->nValue);
    p->nValue = 0;
  }
................................................................................
    }
    p->nStep++;
    if( p->nValue==0 ){
      p->nValue = p->nStep;
    }
  }
}






static void percent_rankValueFunc(sqlite3_context *pCtx){
  struct CallCount *p;
  p = (struct CallCount*)sqlite3_aggregate_context(pCtx, sizeof(*p));
  if( p ){
    if( p->nTotal>1 ){
      double r = (double)(p->nValue-1) / (double)(p->nTotal-1);
      sqlite3_result_double(pCtx, r);
................................................................................
  if( p ){
    if( p->nTotal==0 ){
      p->nTotal = sqlite3_value_int64(apArg[0]);
    }
    p->nStep++;
  }
}






static void cume_distValueFunc(sqlite3_context *pCtx){
  struct CallCount *p;
  p = (struct CallCount*)sqlite3_aggregate_context(pCtx, sizeof(*p));
  if( p && p->nTotal ){
    double r = (double)(p->nStep) / (double)(p->nTotal);
    sqlite3_result_double(pCtx, r);
  }
................................................................................
            pCtx, "argument of ntile must be a positive integer", -1
        );
      }
    }
    p->iRow++;
  }
}






static void ntileValueFunc(sqlite3_context *pCtx){
  struct NtileCtx *p;
  p = (struct NtileCtx*)sqlite3_aggregate_context(pCtx, sizeof(*p));
  if( p && p->nParam>0 ){
    int nSize = (p->nTotal / p->nParam);
    if( nSize==0 ){
      sqlite3_result_int64(pCtx, p->iRow);
................................................................................
    sqlite3_result_value(pCtx, p->pVal);
    sqlite3_value_free(p->pVal);
    p->pVal = 0;
  }
}

/*
** Static names for the built-in window function names.  These static
** names are used, rather than string literals, so that FuncDef objects
** can be associated with a particular window function by direct
** comparison of the zName pointer.  Example:
**
**       if( pFuncDef->zName==row_valueName ){ ... }
*/




static const char row_numberName[] =   "row_number";
static const char dense_rankName[] =   "dense_rank";
static const char rankName[] =         "rank";
static const char percent_rankName[] = "percent_rank";
static const char cume_distName[] =    "cume_dist";
static const char ntileName[] =        "ntile";
static const char last_valueName[] =   "last_value";
static const char nth_valueName[] =    "nth_value";
static const char first_valueName[] =  "first_value";
static const char leadName[] =         "lead";
static const char lagName[] =          "lag";

/*
** No-op implementations of xStep() and xFinalize().  Used as place-holders
** for built-in window functions that never call those interfaces.
**
** The noopValueFunc() is called but is expected to do nothing.  The
** noopStepFunc() is never called, and so it is marked with NO_TEST to
** let the test coverage routine know not to expect this function to be
** invoked.
*/
static void noopStepFunc(    /*NO_TEST*/
  sqlite3_context *p,        /*NO_TEST*/


  int n,                     /*NO_TEST*/
  sqlite3_value **a          /*NO_TEST*/
){                           /*NO_TEST*/
  assert(0);                 /*NO_TEST*/
}                            /*NO_TEST*/
static void noopValueFunc(sqlite3_context *p){ /*no-op*/; }

/* Window functions that use all window interfaces: xStep, xFinal,
** xValue, and xInverse */
#define WINDOWFUNCALL(name,nArg,extra) {                                   \
  nArg, (SQLITE_UTF8|SQLITE_FUNC_WINDOW|extra), 0, 0,                      \


  name ## StepFunc, name ## FinalizeFunc, name ## ValueFunc,               \
  name ## InvFunc, name ## Name                                            \
}

/* Window functions that are implemented using bytecode and thus have
** no-op routines for their methods */
#define WINDOWFUNCNOOP(name,nArg,extra) {                                  \
  nArg, (SQLITE_UTF8|SQLITE_FUNC_WINDOW|extra), 0, 0,                      \
  noopStepFunc, noopValueFunc, noopValueFunc,                              \
  noopStepFunc, name ## Name                                               \
}

/* Window functions that use all window interfaces: xStep, the
** same routine for xFinalize and xValue and which never call
** xInverse. */
#define WINDOWFUNCX(name,nArg,extra) {                                     \
  nArg, (SQLITE_UTF8|SQLITE_FUNC_WINDOW|extra), 0, 0,                      \


  name ## StepFunc, name ## ValueFunc, name ## ValueFunc,                  \
  noopStepFunc, name ## Name                                               \
}


/*
** Register those built-in window functions that are not also aggregates.
*/
void sqlite3WindowFunctions(void){
  static FuncDef aWindowFuncs[] = {
    WINDOWFUNCX(row_number, 0, 0),
    WINDOWFUNCX(dense_rank, 0, 0),
    WINDOWFUNCX(rank, 0, 0),
    WINDOWFUNCX(percent_rank, 0, SQLITE_FUNC_WINDOW_SIZE),
    WINDOWFUNCX(cume_dist, 0, SQLITE_FUNC_WINDOW_SIZE),
    WINDOWFUNCX(ntile, 1, SQLITE_FUNC_WINDOW_SIZE),
    WINDOWFUNCALL(last_value, 1, 0),
    WINDOWFUNCNOOP(nth_value, 2, 0),
    WINDOWFUNCNOOP(first_value, 1, 0),
    WINDOWFUNCNOOP(lead, 1, 0),
    WINDOWFUNCNOOP(lead, 2, 0),
    WINDOWFUNCNOOP(lead, 3, 0),
    WINDOWFUNCNOOP(lag, 1, 0),
    WINDOWFUNCNOOP(lag, 2, 0),
    WINDOWFUNCNOOP(lag, 3, 0),
  };
  sqlite3InsertBuiltinFuncs(aWindowFuncs, ArraySize(aWindowFuncs));
}

/*
** This function is called immediately after resolving the function name
** for a window function within a SELECT statement. Argument pList is a
................................................................................
  if( pFunc->funcFlags & SQLITE_FUNC_WINDOW ){
    sqlite3 *db = pParse->db;
    if( pWin->pFilter ){
      sqlite3ErrorMsg(pParse, 
          "FILTER clause may only be used with aggregate window functions"
      );
    }else
    if( pFunc->zName==row_numberName || pFunc->zName==ntileName ){
      sqlite3ExprDelete(db, pWin->pStart);
      sqlite3ExprDelete(db, pWin->pEnd);
      pWin->pStart = pWin->pEnd = 0;
      pWin->eType = TK_ROWS;
      pWin->eStart = TK_UNBOUNDED;
      pWin->eEnd = TK_CURRENT;
    }else

    if( pFunc->zName==dense_rankName || pFunc->zName==rankName
     || pFunc->zName==percent_rankName || pFunc->zName==cume_distName
    ){
      sqlite3ExprDelete(db, pWin->pStart);
      sqlite3ExprDelete(db, pWin->pEnd);
      pWin->pStart = pWin->pEnd = 0;
      pWin->eType = TK_RANGE;
      pWin->eStart = TK_UNBOUNDED;
      pWin->eEnd = TK_CURRENT;
................................................................................
        assert( pKeyInfo->aSortOrder[0]==0 );
        pKeyInfo->aSortOrder[0] = 1;
      }
      sqlite3VdbeAddOp2(v, OP_OpenEphemeral, pWin->csrApp, 2);
      sqlite3VdbeAppendP4(v, pKeyInfo, P4_KEYINFO);
      sqlite3VdbeAddOp2(v, OP_Integer, 0, pWin->regApp+1);
    }
    else if( p->zName==nth_valueName || p->zName==first_valueName ){
      /* Allocate two registers at pWin->regApp. These will be used to
      ** store the start and end index of the current frame.  */
      assert( pMWin->iEphCsr );
      pWin->regApp = pParse->nMem+1;
      pWin->csrApp = pParse->nTab++;
      pParse->nMem += 2;
      sqlite3VdbeAddOp2(v, OP_OpenDup, pWin->csrApp, pMWin->iEphCsr);
    }
    else if( p->zName==leadName || p->zName==lagName ){
      assert( pMWin->iEphCsr );
      pWin->csrApp = pParse->nTab++;
      sqlite3VdbeAddOp2(v, OP_OpenDup, pWin->csrApp, pMWin->iEphCsr);
    }
  }
}

................................................................................
        sqlite3VdbeAddOp4Int(v, OP_SeekGE, pWin->csrApp, 0, regArg, 1);
        VdbeCoverage(v);
        sqlite3VdbeAddOp1(v, OP_Delete, pWin->csrApp);
        sqlite3VdbeJumpHere(v, sqlite3VdbeCurrentAddr(v)-2);
      }
      sqlite3VdbeJumpHere(v, addrIsNull);
    }else if( pWin->regApp ){
      assert( pWin->pFunc->zName==nth_valueName
           || pWin->pFunc->zName==first_valueName
      );
      assert( bInverse==0 || bInverse==1 );
      sqlite3VdbeAddOp2(v, OP_AddImm, pWin->regApp+1-bInverse, 1);
    }else if( pWin->pFunc->zName==leadName
           || pWin->pFunc->zName==lagName
    ){
      /* no-op */
    }else{
      int addrIf = 0;
      if( pWin->pFilter ){
        int regTmp;
        assert( nArg==pWin->pOwner->x.pList->nExpr );
................................................................................
  int regGosub,
  int addrGosub
){
  Vdbe *v = sqlite3GetVdbe(pParse);
  Window *pWin;
  for(pWin=pMWin; pWin; pWin=pWin->pNextWin){
    FuncDef *pFunc = pWin->pFunc;
    if( pFunc->zName==nth_valueName
     || pFunc->zName==first_valueName
    ){
      int csr = pWin->csrApp;
      int lbl = sqlite3VdbeMakeLabel(v);
      int tmpReg = sqlite3GetTempReg(pParse);
      sqlite3VdbeAddOp2(v, OP_Null, 0, pWin->regResult);

      if( pFunc->zName==nth_valueName ){
        sqlite3VdbeAddOp3(v, OP_Column, pMWin->iEphCsr, pWin->iArgCol+1,tmpReg);
      }else{
        sqlite3VdbeAddOp2(v, OP_Integer, 1, tmpReg);
      }
      sqlite3VdbeAddOp3(v, OP_Add, tmpReg, pWin->regApp, tmpReg);
      sqlite3VdbeAddOp3(v, OP_Gt, pWin->regApp+1, lbl, tmpReg);
      VdbeCoverage(v);
      sqlite3VdbeAddOp3(v, OP_SeekRowid, csr, lbl, tmpReg);
      VdbeCoverage(v);
      sqlite3VdbeAddOp3(v, OP_Column, csr, pWin->iArgCol, pWin->regResult);
      sqlite3VdbeResolveLabel(v, lbl);
      sqlite3ReleaseTempReg(pParse, tmpReg);
    }
    else if( pFunc->zName==leadName || pFunc->zName==lagName ){
      int nArg = pWin->pOwner->x.pList->nExpr;
      int iEph = pMWin->iEphCsr;
      int csr = pWin->csrApp;
      int lbl = sqlite3VdbeMakeLabel(v);
      int tmpReg = sqlite3GetTempReg(pParse);

      if( nArg<3 ){
        sqlite3VdbeAddOp2(v, OP_Null, 0, pWin->regResult);
      }else{
        sqlite3VdbeAddOp3(v, OP_Column, iEph, pWin->iArgCol+2, pWin->regResult);
      }
      sqlite3VdbeAddOp2(v, OP_Rowid, iEph, tmpReg);
      if( nArg<2 ){
        int val = (pFunc->zName==leadName ? 1 : -1);
        sqlite3VdbeAddOp2(v, OP_AddImm, tmpReg, val);
      }else{
        int op = (pFunc->zName==leadName ? OP_Add : OP_Subtract);
        int tmpReg2 = sqlite3GetTempReg(pParse);
        sqlite3VdbeAddOp3(v, OP_Column, iEph, pWin->iArgCol+1, tmpReg2);
        sqlite3VdbeAddOp3(v, op, tmpReg2, tmpReg, tmpReg);
        sqlite3ReleaseTempReg(pParse, tmpReg2);
      }

      sqlite3VdbeAddOp3(v, OP_SeekRowid, csr, lbl, tmpReg);
................................................................................
  int regArg;
  int nArg = 0;
  Window *pWin;
  for(pWin=pMWin; pWin; pWin=pWin->pNextWin){
    FuncDef *pFunc = pWin->pFunc;
    sqlite3VdbeAddOp2(v, OP_Null, 0, pWin->regAccum);
    nArg = MAX(nArg, windowArgCount(pWin));
    if( pFunc->zName==nth_valueName
     || pFunc->zName==first_valueName
    ){
      sqlite3VdbeAddOp2(v, OP_Integer, 0, pWin->regApp);
      sqlite3VdbeAddOp2(v, OP_Integer, 0, pWin->regApp+1);
    }

    if( (pFunc->funcFlags & SQLITE_FUNC_MINMAX) && pWin->csrApp ){
      assert( pWin->eStart!=TK_UNBOUNDED );
................................................................................

    if( pMWin->eStart==TK_CURRENT && pMWin->eEnd==TK_UNBOUNDED ){
      bCache = 1;
    }else{
      for(pWin=pMWin; pWin; pWin=pWin->pNextWin){
        FuncDef *pFunc = pWin->pFunc;
        if( (pFunc->funcFlags & SQLITE_FUNC_WINDOW_SIZE)
         || (pFunc->zName==nth_valueName)
         || (pFunc->zName==first_valueName)
         || (pFunc->zName==leadName)
         || (pFunc->zName==lagName)
        ){
          bCache = 1;
          break;
        }
      }
    }