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Enhance the DELETE logic so that it can make use of WHERE_ONEPASS_DESIRED

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for rowid tables.

FossilOrigin-Name: 8f479a72758ab6fedb171ada612b1963143c32fa
This commit is contained in:
drh
2013-11-16 20:13:39 +00:00
parent aedfc5078a
commit 6a53499a20
7 changed files with 101 additions and 72 deletions
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52
src/delete.c
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@@ -234,12 +234,16 @@ void sqlite3DeleteFrom(
int iTabCur; /* Cursor number for the table */
int iDataCur; /* VDBE cursor for the canonical data source */
int iIdxCur; /* Cursor number of the first index */
int nIdx; /* Number of indices */
sqlite3 *db; /* Main database structure */
AuthContext sContext; /* Authorization context */
NameContext sNC; /* Name context to resolve expressions in */
int iDb; /* Database number */
int memCnt = -1; /* Memory cell used for change counting */
int rcauth; /* Value returned by authorization callback */
int okOnePass; /* True for one-pass algorithm without the FIFO */
int aiCurOnePass[2]; /* The write cursors opened by WHERE_ONEPASS */
u8 *aToOpen = 0; /* Open cursor iTabCur+j if aToOpen[j] is true */
#ifndef SQLITE_OMIT_TRIGGER
int isView; /* True if attempting to delete from a view */
@@ -295,11 +299,11 @@ void sqlite3DeleteFrom(
}
assert(!isView || pTrigger);
/* Assign cursor number to the table and all its indices.
/* Assign cursor numbers to the table and all its indices.
*/
assert( pTabList->nSrc==1 );
iTabCur = pTabList->a[0].iCursor = pParse->nTab++;
for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
for(nIdx=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, nIdx++){
pParse->nTab++;
}
@@ -399,8 +403,8 @@ void sqlite3DeleteFrom(
/* Open cursors for all indices of the table.
*/
sqlite3OpenTableAndIndices(pParse, pTab, OP_OpenWrite,
iTabCur, &iDataCur, &iIdxCur);
sqlite3OpenTableAndIndices(pParse, pTab, OP_OpenWrite, iTabCur, aToOpen,
&iDataCur, &iIdxCur);
/* Loop over the primary keys to be deleted. */
addr = sqlite3VdbeAddOp1(v, OP_Rewind, iEph);
@@ -424,22 +428,39 @@ void sqlite3DeleteFrom(
** all rowids to be deleted into a RowSet.
*/
int iRowSet = ++pParse->nMem; /* Register for rowset of rows to delete */
int iRowid = ++pParse->nMem; /* Used for storing rowid values. */
int regRowid; /* Actual register containing rowids */
/* Collect rowids of every row to be deleted.
*/
sqlite3VdbeAddOp2(v, OP_Null, 0, iRowSet);
pWInfo = sqlite3WhereBegin(
pParse, pTabList, pWhere, 0, 0, WHERE_DUPLICATES_OK, 0
pParse, pTabList, pWhere, 0, 0,
WHERE_DUPLICATES_OK|WHERE_ONEPASS_DESIRED, iTabCur+1
);
if( pWInfo==0 ) goto delete_from_cleanup;
regRowid = sqlite3ExprCodeGetColumn(pParse, pTab, -1, iTabCur, iRowid, 0);
sqlite3VdbeAddOp2(v, OP_RowSetAdd, iRowSet, regRowid);
okOnePass = sqlite3WhereOkOnePass(pWInfo, aiCurOnePass);
if( db->flags & SQLITE_CountRows ){
sqlite3VdbeAddOp2(v, OP_AddImm, memCnt, 1);
}
regRowid = sqlite3ExprCodeGetColumn(pParse, pTab, -1, iTabCur,
pParse->nMem+1, 0);
if( regRowid>pParse->nMem ) pParse->nMem = regRowid;
if( okOnePass ){
aToOpen = sqlite3DbMallocRaw(db, nIdx+2);
if( aToOpen==0 ) goto delete_from_cleanup;
memset(aToOpen, 1, nIdx+1);
aToOpen[nIdx+1] = 0;
if( aiCurOnePass[0]>=0 ) aToOpen[aiCurOnePass[0]-iTabCur] = 0;
if( aiCurOnePass[1]>=0 ) aToOpen[aiCurOnePass[1]-iTabCur] = 0;
addr = sqlite3VdbeAddOp0(v, OP_Goto);
}else{
sqlite3VdbeAddOp2(v, OP_RowSetAdd, iRowSet, regRowid);
}
sqlite3WhereEnd(pWInfo);
if( okOnePass ){
sqlite3VdbeAddOp0(v, OP_Halt);
sqlite3VdbeJumpHere(v, addr);
}
/* Delete every item whose key was written to the list during the
** database scan. We have to delete items after the scan is complete
@@ -451,20 +472,22 @@ void sqlite3DeleteFrom(
** only effect this statement has is to fire the INSTEAD OF
** triggers. */
if( !isView ){
sqlite3OpenTableAndIndices(pParse, pTab, OP_OpenWrite, iTabCur,
sqlite3OpenTableAndIndices(pParse, pTab, OP_OpenWrite, iTabCur, aToOpen,
&iDataCur, &iIdxCur);
assert( iDataCur==iTabCur );
assert( iIdxCur==iDataCur+1 );
}
addr = sqlite3VdbeAddOp3(v, OP_RowSetRead, iRowSet, end, iRowid);
if( !okOnePass ){
addr = sqlite3VdbeAddOp3(v, OP_RowSetRead, iRowSet, end, regRowid);
}
/* Delete the row */
#ifndef SQLITE_OMIT_VIRTUALTABLE
if( IsVirtual(pTab) ){
const char *pVTab = (const char *)sqlite3GetVTable(db, pTab);
sqlite3VtabMakeWritable(pParse, pTab);
sqlite3VdbeAddOp4(v, OP_VUpdate, 0, 1, iRowid, pVTab, P4_VTAB);
sqlite3VdbeAddOp4(v, OP_VUpdate, 0, 1, regRowid, pVTab, P4_VTAB);
sqlite3VdbeChangeP5(v, OE_Abort);
sqlite3MayAbort(pParse);
}else
@@ -472,11 +495,13 @@ void sqlite3DeleteFrom(
{
int count = (pParse->nested==0); /* True to count changes */
sqlite3GenerateRowDelete(pParse, pTab, pTrigger, iDataCur, iIdxCur,
iRowid, 1, count, OE_Default, 0);
regRowid, 1, count, OE_Default, okOnePass);
}
/* End of the delete loop */
sqlite3VdbeAddOp2(v, OP_Goto, 0, addr);
if( !okOnePass ){
sqlite3VdbeAddOp2(v, OP_Goto, 0, addr);
}
sqlite3VdbeResolveLabel(v, end);
/* Close the cursors open on the table and its indexes. */
@@ -510,6 +535,7 @@ delete_from_cleanup:
sqlite3AuthContextPop(&sContext);
sqlite3SrcListDelete(db, pTabList);
sqlite3ExprDelete(db, pWhere);
sqlite3DbFree(db, aToOpen);
return;
}
/* Make sure "isView" and other macros defined above are undefined. Otherwise