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Rewrite the aggregate handling logic so that it runs in O(1) space.

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This is the first cut at the code.  Many regression tests fail. (CVS 2662)

FossilOrigin-Name: 17039ec3ff4396862beedf4a8af89654b2140f58
This commit is contained in:
drh
2005-09-07 21:22:45 +00:00
parent 79158e1865
commit 13449892ef
14 changed files with 701 additions and 806 deletions
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200
src/expr.c
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@@ -12,7 +12,7 @@
** This file contains routines used for analyzing expressions and
** for generating VDBE code that evaluates expressions in SQLite.
**
** $Id: expr.c,v 1.224 2005/09/05 20:06:49 drh Exp $
** $Id: expr.c,v 1.225 2005/09/07 21:22:46 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>
@@ -695,6 +695,7 @@ static int exprNodeIsConstant(void *pArg, Expr *pExpr){
case TK_COLUMN:
case TK_DOT:
case TK_AGG_FUNCTION:
case TK_AGG_COLUMN:
#ifndef SQLITE_OMIT_SUBQUERY
case TK_SELECT:
case TK_EXISTS:
@@ -1230,11 +1231,19 @@ int sqlite3ExprResolveNames(
NameContext *pNC, /* Namespace to resolve expressions in. */
Expr *pExpr /* The expression to be analyzed. */
){
int savedHasAgg;
if( pExpr==0 ) return 0;
savedHasAgg = pNC->hasAgg;
pNC->hasAgg = 0;
walkExprTree(pExpr, nameResolverStep, pNC);
if( pNC->nErr>0 ){
ExprSetProperty(pExpr, EP_Error);
}
if( pNC->hasAgg ){
ExprSetProperty(pExpr, EP_Agg);
}else if( savedHasAgg ){
pNC->hasAgg = 1;
}
return ExprHasProperty(pExpr, EP_Error);
}
@@ -1287,10 +1296,6 @@ void sqlite3CodeSubselect(Parse *pParse, Expr *pExpr){
sqlite3VdbeAddOp(v, OP_MemStore, mem, 1);
}
if( pExpr->pSelect ){
sqlite3VdbeAddOp(v, OP_AggContextPush, 0, 0);
}
switch( pExpr->op ){
case TK_IN: {
char affinity;
@@ -1403,9 +1408,6 @@ void sqlite3CodeSubselect(Parse *pParse, Expr *pExpr){
}
}
if( pExpr->pSelect ){
sqlite3VdbeAddOp(v, OP_AggContextPop, 0, 0);
}
if( testAddr ){
sqlite3VdbeChangeP2(v, testAddr, sqlite3VdbeCurrentAddr(v));
}
@@ -1448,10 +1450,21 @@ void sqlite3ExprCode(Parse *pParse, Expr *pExpr){
}
op = pExpr->op;
switch( op ){
case TK_AGG_COLUMN: {
AggInfo *pAggInfo = pExpr->pAggInfo;
struct AggInfo_col *pCol = &pAggInfo->aCol[pExpr->iAgg];
if( !pAggInfo->directMode ){
sqlite3VdbeAddOp(v, OP_MemLoad, pCol->iMem, 0);
break;
}else if( pAggInfo->useSortingIdx ){
sqlite3VdbeAddOp(v, OP_Column, pAggInfo->sortingIdx,
pCol->iSorterColumn);
break;
}
/* Otherwise, fall thru into the TK_COLUMN case */
}
case TK_COLUMN: {
if( !pParse->fillAgg && pExpr->iAgg>=0 ){
sqlite3VdbeAddOp(v, OP_AggGet, pExpr->iAggCtx, pExpr->iAgg);
}else if( pExpr->iColumn>=0 ){
if( pExpr->iColumn>=0 ){
sqlite3VdbeAddOp(v, OP_Column, pExpr->iTable, pExpr->iColumn);
sqlite3ColumnDefault(v, pExpr->pTab, pExpr->iColumn);
}else{
@@ -1600,7 +1613,8 @@ void sqlite3ExprCode(Parse *pParse, Expr *pExpr){
break;
}
case TK_AGG_FUNCTION: {
sqlite3VdbeAddOp(v, OP_AggGet, 0, pExpr->iAgg);
AggInfo *pInfo = pExpr->pAggInfo;
sqlite3VdbeAddOp(v, OP_MemLoad, pInfo->aFunc[pExpr->iAgg].iMem, 0);
break;
}
case TK_CONST_FUNC:
@@ -1610,7 +1624,7 @@ void sqlite3ExprCode(Parse *pParse, Expr *pExpr){
FuncDef *pDef;
int nId;
const char *zId;
int p2 = 0;
int constMask = 0;
int i;
u8 enc = pParse->db->enc;
CollSeq *pColl = 0;
@@ -1621,7 +1635,7 @@ void sqlite3ExprCode(Parse *pParse, Expr *pExpr){
nExpr = sqlite3ExprCodeExprList(pParse, pList);
for(i=0; i<nExpr && i<32; i++){
if( sqlite3ExprIsConstant(pList->a[i].pExpr) ){
p2 |= (1<<i);
constMask |= (1<<i);
}
if( pDef->needCollSeq && !pColl ){
pColl = sqlite3ExprCollSeq(pParse, pList->a[i].pExpr);
@@ -1631,7 +1645,7 @@ void sqlite3ExprCode(Parse *pParse, Expr *pExpr){
if( !pColl ) pColl = pParse->db->pDfltColl;
sqlite3VdbeOp3(v, OP_CollSeq, 0, 0, (char *)pColl, P3_COLLSEQ);
}
sqlite3VdbeOp3(v, OP_Function, nExpr, p2, (char*)pDef, P3_FUNCDEF);
sqlite3VdbeOp3(v, OP_Function, constMask, nExpr, (char*)pDef, P3_FUNCDEF);
break;
}
#ifndef SQLITE_OMIT_SUBQUERY
@@ -2047,23 +2061,32 @@ int sqlite3ExprCompare(Expr *pA, Expr *pB){
return 1;
}
/*
** Add a new element to the pParse->aAgg[] array and return its index.
** The new element is initialized to zero. The calling function is
** expected to fill it in.
** Add a new element to the pAggInfo->aCol[] array. Return the index of
** the new element. Return a negative number if malloc fails.
*/
static int appendAggInfo(Parse *pParse){
if( (pParse->nAgg & 0x7)==0 ){
int amt = pParse->nAgg + 8;
AggExpr *aAgg = sqliteRealloc(pParse->aAgg, amt*sizeof(pParse->aAgg[0]));
if( aAgg==0 ){
return -1;
}
pParse->aAgg = aAgg;
static int addAggInfoColumn(AggInfo *pInfo){
int i;
i = sqlite3ArrayAllocate((void**)&pInfo->aCol, sizeof(pInfo->aCol[0]), 3);
if( i<0 ){
return -1;
}
memset(&pParse->aAgg[pParse->nAgg], 0, sizeof(pParse->aAgg[0]));
return pParse->nAgg++;
}
return i;
}
/*
** Add a new element to the pAggInfo->aFunc[] array. Return the index of
** the new element. Return a negative number if malloc fails.
*/
static int addAggInfoFunc(AggInfo *pInfo){
int i;
i = sqlite3ArrayAllocate((void**)&pInfo->aFunc, sizeof(pInfo->aFunc[0]), 2);
if( i<0 ){
return -1;
}
return i;
}
/*
** This is an xFunc for walkExprTree() used to implement
@@ -2074,63 +2097,112 @@ static int appendAggInfo(Parse *pParse){
*/
static int analyzeAggregate(void *pArg, Expr *pExpr){
int i;
AggExpr *pAgg;
NameContext *pNC = (NameContext *)pArg;
Parse *pParse = pNC->pParse;
SrcList *pSrcList = pNC->pSrcList;
AggInfo *pAggInfo = pNC->pAggInfo;
switch( pExpr->op ){
case TK_COLUMN: {
for(i=0; pSrcList && i<pSrcList->nSrc; i++){
if( pExpr->iTable==pSrcList->a[i].iCursor ){
pAgg = pParse->aAgg;
for(i=0; i<pParse->nAgg; i++, pAgg++){
Expr *pE;
if( pAgg->isAgg ) continue;
pE = pAgg->pExpr;
if( pE->iTable==pExpr->iTable && pE->iColumn==pExpr->iColumn ){
break;
/* Check to see if the column is in one of the tables in the FROM
** clause of the aggregate query */
if( pSrcList ){
struct SrcList_item *pItem = pSrcList->a;
for(i=0; i<pSrcList->nSrc; i++, pItem++){
struct AggInfo_col *pCol;
if( pExpr->iTable==pItem->iCursor ){
/* If we reach this point, it means that pExpr refers to a table
** that is in the FROM clause of the aggregate query.
**
** Make an entry for the column in pAggInfo->aCol[] if there
** is not an entry there already.
*/
pCol = pAggInfo->aCol;
for(i=0; i<pAggInfo->nColumn; i++, pCol++){
if( pCol->iTable==pExpr->iTable &&
pCol->iColumn==pExpr->iColumn ){
break;
}
}
}
if( i>=pParse->nAgg ){
i = appendAggInfo(pParse);
if( i<0 ) return 1;
pAgg = &pParse->aAgg[i];
pAgg->isAgg = 0;
pAgg->pExpr = pExpr;
}
pExpr->iAgg = i;
pExpr->iAggCtx = pNC->nDepth;
return 1;
}
if( i>=pAggInfo->nColumn && (i = addAggInfoColumn(pAggInfo))>=0 ){
pCol = &pAggInfo->aCol[i];
pCol->iTable = pExpr->iTable;
pCol->iColumn = pExpr->iColumn;
pCol->iMem = pParse->nMem++;
pCol->iSorterColumn = -1;
if( pAggInfo->pGroupBy ){
int j, n;
ExprList *pGB = pAggInfo->pGroupBy;
struct ExprList_item *pTerm = pGB->a;
n = pGB->nExpr;
for(j=0; j<n; j++, pTerm++){
Expr *pE = pTerm->pExpr;
if( pE->op==TK_COLUMN && pE->iTable==pExpr->iTable &&
pE->iColumn==pExpr->iColumn ){
pCol->iSorterColumn = j;
break;
}
}
}
if( pCol->iSorterColumn<0 ){
pCol->iSorterColumn = pAggInfo->nSortingColumn++;
}
}
/* There is now an entry for pExpr in pAggInfo->aCol[] (either
** because it was there before or because we just created it).
** Convert the pExpr to be a TK_AGG_COLUMN referring to that
** pAggInfo->aCol[] entry.
*/
pExpr->pAggInfo = pAggInfo;
pExpr->op = TK_AGG_COLUMN;
pExpr->iAgg = i;
break;
} /* endif pExpr->iTable==pItem->iCursor */
} /* end loop over pSrcList */
}
return 1;
}
case TK_AGG_FUNCTION: {
/* The pNC->nDepth==0 test causes aggregate functions in subqueries
** to be ignored */
if( pNC->nDepth==0 ){
pAgg = pParse->aAgg;
for(i=0; i<pParse->nAgg; i++, pAgg++){
if( !pAgg->isAgg ) continue;
if( sqlite3ExprCompare(pAgg->pExpr, pExpr) ){
/* Check to see if pExpr is a duplicate of another aggregate
** function that is already in the pAggInfo structure
*/
struct AggInfo_func *pItem = pAggInfo->aFunc;
for(i=0; i<pAggInfo->nFunc; i++, pItem++){
if( sqlite3ExprCompare(pItem->pExpr, pExpr) ){
break;
}
}
if( i>=pParse->nAgg ){
if( i>=pAggInfo->nFunc ){
/* pExpr is original. Make a new entry in pAggInfo->aFunc[]
*/
u8 enc = pParse->db->enc;
i = appendAggInfo(pParse);
if( i<0 ) return 1;
pAgg = &pParse->aAgg[i];
pAgg->isAgg = 1;
pAgg->pExpr = pExpr;
pAgg->pFunc = sqlite3FindFunction(pParse->db,
pExpr->token.z, pExpr->token.n,
pExpr->pList ? pExpr->pList->nExpr : 0, enc, 0);
i = addAggInfoFunc(pAggInfo);
if( i>=0 ){
pItem = &pAggInfo->aFunc[i];
pItem->pExpr = pExpr;
pItem->iMem = pParse->nMem++;
pItem->pFunc = sqlite3FindFunction(pParse->db,
pExpr->token.z, pExpr->token.n,
pExpr->pList ? pExpr->pList->nExpr : 0, enc, 0);
}
}
/* Make pExpr point to the appropriate pAggInfo->aFunc[] entry
*/
pExpr->iAgg = i;
pExpr->pAggInfo = pAggInfo;
return 1;
}
}
}
/* Recursively walk subqueries looking for TK_COLUMN nodes that need
** to be changed to TK_AGG_COLUMN. But increment nDepth so that
** TK_AGG_FUNCTION nodes in subqueries will be unchanged.
*/
if( pExpr->pSelect ){
pNC->nDepth++;
walkSelectExpr(pExpr->pSelect, analyzeAggregate, pNC);