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Support other frame types that use "<expr> PRECEDING" or "<expr> FOLLOWING" as

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start or end conditions.

FossilOrigin-Name: ec7b648c7f0ee266653561bbb9daa45b9be0d8a1a14f11dc93bce467c35154e6
This commit is contained in:
dan
2018-05-24 17:49:14 +00:00
parent c3a20c19a8
commit 99652dda3c
5 changed files with 183 additions and 91 deletions
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161
src/window.c
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@@ -93,6 +93,50 @@ static void windowCheckFrameValue(Parse *pParse, int reg, int bEnd){
sqlite3VdbeAppendP4(v, (void*)azErr[bEnd], P4_STATIC);
}
/*
** ROWS BETWEEN <expr> PRECEDING AND <expr> FOLLOWING
**
** ...
** if( new partition ){
** Gosub flush_partition
** }
** Insert (record in eph-table)
** sqlite3WhereEnd()
** Gosub flush_partition
**
** flush_partition:
** OpenDup (csr -> csr2)
** OpenDup (csr -> csr3)
** regPrec = <expr1> // PRECEDING expression
** regFollow = <expr2> // FOLLOWING expression
** if( regPrec<0 || regFollow<0 ) throw exception!
** Rewind (csr,csr2,csr3) // if EOF goto flush_partition_done
** Aggstep (csr3)
** Next(csr3) // if EOF fall-through
** if( (regFollow--)<=0 ){
** AggFinal (xValue)
** Gosub addrGosub
** Next(csr) // if EOF goto flush_partition_done
** if( (regPrec--)<=0 ){
** AggStep (csr2, xInverse)
** Next(csr2)
** }
** }
** flush_partition_done:
** Close (csr2)
** Close (csr3)
** ResetSorter (csr)
** Return
**
** ROWS BETWEEN <expr> PRECEDING AND CURRENT ROW
** ROWS BETWEEN CURRENT ROW AND <expr> FOLLOWING
** ROWS BETWEEN <expr> PRECEDING AND UNBOUNDED FOLLOWING
** ROWS BETWEEN UNBOUNDED PRECEDING AND <expr> FOLLOWING
**
** These are similar to the above. For "CURRENT ROW", intialize the
** register to 0. For "UNBOUNDED ..." to infinity.
**
*/
static void windowCodeRowExprStep(
Parse *pParse,
Select *p,
@@ -123,6 +167,15 @@ static void windowCodeRowExprStep(
int addrIfPos1;
int addrIfPos2;
assert( pMWin->eStart==TK_PRECEDING
|| pMWin->eStart==TK_CURRENT
|| pMWin->eStart==TK_UNBOUNDED
);
assert( pMWin->eEnd==TK_FOLLOWING
|| pMWin->eEnd==TK_CURRENT
|| pMWin->eEnd==TK_UNBOUNDED
);
pParse->nMem += nSub + 2;
/* Allocate register and label for the "flush_partition" sub-routine. */
@@ -173,17 +226,22 @@ static void windowCodeRowExprStep(
sqlite3VdbeAddOp2(v, OP_OpenDup, csrPrec, pMWin->iEphCsr);
sqlite3VdbeAddOp2(v, OP_OpenDup, csrFollow, pMWin->iEphCsr);
sqlite3ExprCode(pParse, pMWin->pStart, regPrec);
sqlite3ExprCode(pParse, pMWin->pEnd, regFollow);
/* If either regPrec or regFollow are not non-negative integers, throw
** an exception. */
if( pMWin->pStart ){
assert( pMWin->eStart==TK_PRECEDING );
sqlite3ExprCode(pParse, pMWin->pStart, regPrec);
windowCheckFrameValue(pParse, regPrec, 0);
}
if( pMWin->pEnd ){
assert( pMWin->eEnd==TK_FOLLOWING );
sqlite3ExprCode(pParse, pMWin->pEnd, regFollow);
windowCheckFrameValue(pParse, regFollow, 1);
}
sqlite3VdbeAddOp2(v, OP_Null, 0, pMWin->regResult);
sqlite3VdbeAddOp2(v, OP_Null, 0, pMWin->regAccum);
/* If either regPrec or regFollow are not non-negative integers, throw an
** exception. */
windowCheckFrameValue(pParse, regPrec, 0);
windowCheckFrameValue(pParse, regFollow, 1);
sqlite3VdbeAddOp2(v, OP_Rewind, pMWin->iEphCsr, addrDone);
sqlite3VdbeAddOp2(v, OP_Rewind, csrPrec, addrDone);
sqlite3VdbeChangeP5(v, 1);
@@ -205,9 +263,17 @@ static void windowCodeRowExprStep(
sqlite3VdbeAppendP4(v, pWin->pFunc, P4_FUNCDEF);
sqlite3VdbeChangeP5(v, (u8)pWin->nArg);
}
sqlite3VdbeJumpHere(v, addrNext+1);
if( pMWin->eEnd==TK_UNBOUNDED ){
sqlite3VdbeAddOp2(v, OP_Goto, 0, addrNext);
sqlite3VdbeJumpHere(v, addrNext+1);
addrNext = sqlite3VdbeCurrentAddr(v);
}else{
sqlite3VdbeJumpHere(v, addrNext+1);
}
addrIfPos1 = sqlite3VdbeAddOp3(v, OP_IfPos, regFollow, 0 , 1);
if( pMWin->eEnd==TK_FOLLOWING ){
addrIfPos1 = sqlite3VdbeAddOp3(v, OP_IfPos, regFollow, 0 , 1);
}
for(pWin=pMWin; pWin; pWin=pWin->pNextWin){
sqlite3VdbeAddOp3(v,
OP_AggFinal, pWin->regAccum, pWin->nArg, pWin->regResult
@@ -218,20 +284,27 @@ static void windowCodeRowExprStep(
sqlite3VdbeAddOp2(v, OP_Next, pMWin->iEphCsr, sqlite3VdbeCurrentAddr(v)+2);
sqlite3VdbeAddOp2(v, OP_Goto, 0, addrDone);
addrIfPos2 = sqlite3VdbeAddOp3(v, OP_IfPos, regPrec, 0 , 1);
sqlite3VdbeAddOp2(v, OP_Next, csrPrec, sqlite3VdbeCurrentAddr(v)+1);
for(pWin=pMWin; pWin; pWin=pWin->pNextWin){
int i;
for(i=0; i<pWin->nArg; i++){
sqlite3VdbeAddOp3(v, OP_Column, csrPrec, pWin->iArgCol+i, reg+i);
if( pMWin->eStart==TK_CURRENT || pMWin->eStart==TK_PRECEDING ){
if( pMWin->eStart==TK_PRECEDING ){
addrIfPos2 = sqlite3VdbeAddOp3(v, OP_IfPos, regPrec, 0 , 1);
}
sqlite3VdbeAddOp2(v, OP_Next, csrPrec, sqlite3VdbeCurrentAddr(v)+1);
for(pWin=pMWin; pWin; pWin=pWin->pNextWin){
int i;
for(i=0; i<pWin->nArg; i++){
sqlite3VdbeAddOp3(v, OP_Column, csrPrec, pWin->iArgCol+i, reg+i);
}
sqlite3VdbeAddOp3(v, OP_AggStep0, 1, reg, pWin->regAccum);
sqlite3VdbeAppendP4(v, pWin->pFunc, P4_FUNCDEF);
sqlite3VdbeChangeP5(v, (u8)pWin->nArg);
}
if( pMWin->eStart==TK_PRECEDING ){
sqlite3VdbeJumpHere(v, addrIfPos2);
}
sqlite3VdbeAddOp3(v, OP_AggStep0, 1, reg, pWin->regAccum);
sqlite3VdbeAppendP4(v, pWin->pFunc, P4_FUNCDEF);
sqlite3VdbeChangeP5(v, (u8)pWin->nArg);
}
sqlite3VdbeJumpHere(v, addrIfPos2);
sqlite3VdbeJumpHere(v, addrIfPos1);
if( pMWin->eEnd==TK_FOLLOWING ){
sqlite3VdbeJumpHere(v, addrIfPos1);
}
sqlite3VdbeAddOp2(v, OP_Goto, 0, addrNext);
/* flush_partition_done: */
@@ -428,48 +501,6 @@ static void windowCodeDefaultStep(
**
**========================================================================
**
** ROWS BETWEEN <expr> PRECEDING AND <expr> FOLLOWING
**
** ...
** if( new partition ){
** Gosub flush_partition
** }
** Insert (record in eph-table)
** sqlite3WhereEnd()
** Gosub flush_partition
**
** flush_partition:
** OpenDup (csr -> csr2)
** OpenDup (csr -> csr3)
** regPrec = <expr1> // PRECEDING expression
** regFollow = <expr2> // FOLLOWING expression
** if( regPrec<0 || regFollow<0 ) throw exception!
** Rewind (csr,csr2,csr3) // if EOF goto flush_partition_done
** Aggstep (csr3)
** Next(csr3) // if EOF fall-through
** if( (regFollow--)<=0 ){
** AggFinal (xValue)
** Gosub addrGosub
** Next(csr) // if EOF goto flush_partition_done
** if( (regPrec--)<=0 ){
** AggStep (csr2, xInverse)
** Next(csr2)
** }
** }
** flush_partition_done:
** Close (csr2)
** Close (csr3)
** ResetSorter (csr)
** Return
**
** ROWS BETWEEN <expr> PRECEDING AND CURRENT ROW
** ROWS BETWEEN CURRENT ROW AND <expr> FOLLOWING
** ROWS BETWEEN <expr> PRECEDING AND UNBOUNDED FOLLOWING
** ROWS BETWEEN UNBOUNDED PRECEDING AND <expr> FOLLOWING
**
** These are similar to the above. For "CURRENT ROW", intialize the
** register to 0. For "UNBOUNDED ..." to infinity.
**
** ROWS BETWEEN <expr> PRECEDING AND <expr> PRECEDING
**
** Replace the bit after "Rewind" in the above with:
@@ -522,8 +553,8 @@ void sqlite3WindowCodeStep(
Window *pMWin = p->pWin;
if( pMWin->eType==TK_ROWS
&& pMWin->eStart==TK_PRECEDING
&& pMWin->eEnd==TK_FOLLOWING
&& (pMWin->eStart==TK_PRECEDING || pMWin->eEnd==TK_FOLLOWING)
&& (pMWin->eStart!=TK_FOLLOWING || pMWin->eEnd==TK_PRECEDING)
){
*pbLoop = 0;
windowCodeRowExprStep(pParse, p, pWInfo, regGosub, addrGosub);