database/sqlite
1
0
Fork 0
mirror of https://github.com/sqlite/sqlite.git synced 2025-11-11 01:42:22 +03:00
Code Activity

Combine the rowid and WITHOUT ROWID paths for DELETE into a single path.

Browse Source 
FossilOrigin-Name: c4734b881a64a9d21d03a14e901785797577fbd8
This commit is contained in:
drh
2013-11-16 22:48:52 +00:00
parent 156c7919d9
commit 9612947260
3 changed files with 115 additions and 125 deletions
Download Patch File Download Diff File Expand all files Collapse all files

226
src/delete.c
View File

@@ -227,7 +227,6 @@ void sqlite3DeleteFrom(
Vdbe *v; /* The virtual database engine */
Table *pTab; /* The table from which records will be deleted */
const char *zDb; /* Name of database holding pTab */
int end, addr = 0; /* A couple addresses of generated code */
int i; /* Loop counter */
WhereInfo *pWInfo; /* Information about the WHERE clause */
Index *pIdx; /* For looping over indices of the table */
@@ -244,7 +243,18 @@ void sqlite3DeleteFrom(
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 */
Index *pPk; /* The PRIMARY KEY index on the table */
int iPk; /* First of nPk registerss holding PRIMARY KEY value */
i16 nPk = 1; /* Number of components of the PRIMARY KEY */
int iKey; /* Memory cell holding row key of to be deleted */
i16 nKey; /* Number of memory cells of row key */
int iEphCur = 0; /* Ephemeral table holding all primary key values */
int iRowSet = 0; /* Register for rowset of rows to delete */
int addrBypass = 0; /* Address of jump over the delete logic */
int addrLoop = 0; /* Top of the delete loop */
int addrDelete = 0; /* Jump directly to the delete logic */
int addrEphOpen = 0; /* Instruction to open the Ephermeral table */
#ifndef SQLITE_OMIT_TRIGGER
int isView; /* True if attempting to delete from a view */
Trigger *pTrigger; /* List of table triggers, if required */
@@ -369,146 +379,121 @@ void sqlite3DeleteFrom(
}
}else
#endif /* SQLITE_OMIT_TRUNCATE_OPTIMIZATION */
if( !HasRowid(pTab) ){
/* There is a WHERE clause on a WITHOUT ROWID table.
{
if( HasRowid(pTab) ){
/* For a rowid table, initialize the RowSet to an empty set */
pPk = 0;
nPk = 1;
iRowSet = ++pParse->nMem;
sqlite3VdbeAddOp2(v, OP_Null, 0, iRowSet);
}else{
/* For a WITHOUT ROWID table, create an ephermeral table used to
** hold all primary keys for rows to be deleted. */
pPk = sqlite3PrimaryKeyIndex(pTab);
assert( pPk!=0 );
nPk = pPk->nKeyCol;
iPk = pParse->nMem+1;
pParse->nMem += nPk;
iEphCur = pParse->nTab++;
addrEphOpen = sqlite3VdbeAddOp2(v, OP_OpenEphemeral, iEphCur, nPk);
sqlite3VdbeSetP4KeyInfo(pParse, pPk);
}
/* Construct a query to find the rowid or primary key for every row
** to be deleted, based on the WHERE clause.
*/
Index *pPk; /* The PRIMARY KEY index on the table */
int iPk; /* First of nPk memory cells holding PRIMARY KEY value */
int iEph; /* Ephemeral table holding all primary key values */
int iKey; /* Key value inserting into iEph */
i16 nPk; /* Number of components of the PRIMARY KEY */
pPk = sqlite3PrimaryKeyIndex(pTab);
assert( pPk!=0 );
nPk = pPk->nKeyCol;
iPk = pParse->nMem+1;
pParse->nMem += nPk;
iKey = ++pParse->nMem;
iEph = pParse->nTab++;
addr = sqlite3VdbeAddOp2(v, OP_OpenEphemeral, iEph, nPk);
sqlite3VdbeSetP4KeyInfo(pParse, pPk);
pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere, 0, 0,
WHERE_ONEPASS_DESIRED, iTabCur+1);
if( pWInfo==0 ) goto delete_from_cleanup;
okOnePass = sqlite3WhereOkOnePass(pWInfo, aiCurOnePass);
for(i=0; i<nPk; i++){
sqlite3ExprCodeGetColumnOfTable(v, pTab, iTabCur, pPk->aiColumn[i],iPk+i);
}
/* Keep track of the number of rows to be deleted */
if( db->flags & SQLITE_CountRows ){
sqlite3VdbeAddOp2(v, OP_AddImm, memCnt, 1);
}
/* Extract the rowid or primary key for the current row */
if( pPk ){
for(i=0; i<nPk; i++){
sqlite3ExprCodeGetColumnOfTable(v, pTab, iTabCur,
pPk->aiColumn[i], iPk+i);
}
iKey = iPk;
nKey = nPk;
}else{
iKey = pParse->nMem + 1;
iKey = sqlite3ExprCodeGetColumn(pParse, pTab, -1, iTabCur, iKey, 0);
if( iKey>pParse->nMem ) pParse->nMem = iKey;
}
if( okOnePass ){
/* For ONEPASS, no need to store the rowid/primary-key. There is only
** one, so just keep it in its register(s) and fall through to the
** delete code.
*/
nKey = nPk; /* OP_Found will use an unpacked key */
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;
sqlite3VdbeChangeToNoop(v, addr);
addr = sqlite3VdbeAddOp0(v, OP_Goto);
}else{
if( addrEphOpen ) sqlite3VdbeChangeToNoop(v, addrEphOpen);
addrDelete = sqlite3VdbeAddOp0(v, OP_Goto); /* Jump to DELETE logic */
}else if( pPk ){
/* Construct a composite key for the row to be deleted and remember it */
iKey = ++pParse->nMem;
nKey = 0; /* Zero tells OP_Found to use a composite key */
sqlite3VdbeAddOp4(v, OP_MakeRecord, iPk, nPk, iKey,
sqlite3IndexAffinityStr(v, pPk), P4_TRANSIENT);
sqlite3VdbeAddOp2(v, OP_IdxInsert, iEph, iKey);
}
sqlite3WhereEnd(pWInfo);
if( okOnePass ){
sqlite3VdbeAddOp0(v, OP_Halt);
sqlite3VdbeJumpHere(v, addr);
}
/* Open cursors for all indices of the table.
*/
sqlite3OpenTableAndIndices(pParse, pTab, OP_OpenWrite, iTabCur, aToOpen,
&iDataCur, &iIdxCur);
/* Loop over the primary keys to be deleted. */
if( !okOnePass ){
addr = sqlite3VdbeAddOp1(v, OP_Rewind, iEph);
sqlite3VdbeAddOp2(v, OP_RowKey, iEph, iPk);
}
/* Delete the row */
sqlite3GenerateRowDelete(pParse, pTab, pTrigger, iDataCur, iIdxCur,
iPk, nPk*okOnePass, 1, OE_Default, okOnePass);
/* End of the delete loop */
if( !okOnePass ){
sqlite3VdbeAddOp2(v, OP_Next, iEph, addr+1);
sqlite3VdbeJumpHere(v, addr);
}
/* Close the cursors open on the table and its indexes. */
assert( iDataCur>=iIdxCur );
for(i=0, pIdx=pTab->pIndex; pIdx; i++, pIdx=pIdx->pNext){
sqlite3VdbeAddOp1(v, OP_Close, iIdxCur+i);
}
}else{
/* There is a WHERE clause on a rowid table. Run a loop that extracts
** all rowids to be deleted into a RowSet.
*/
int iRowSet = ++pParse->nMem; /* Register for rowset of rows to delete */
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|WHERE_ONEPASS_DESIRED, iTabCur+1
);
if( pWInfo==0 ) goto delete_from_cleanup;
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);
sqlite3VdbeAddOp2(v, OP_IdxInsert, iEphCur, iKey);
}else{
sqlite3VdbeAddOp2(v, OP_RowSetAdd, iRowSet, regRowid);
/* Get the rowid of the row to be deleted and remember it in the RowSet */
nKey = 1; /* OP_Seek always uses a single rowid */
sqlite3VdbeAddOp2(v, OP_RowSetAdd, iRowSet, iKey);
}
/* End of the WHERE loop */
sqlite3WhereEnd(pWInfo);
if( okOnePass ){
sqlite3VdbeAddOp0(v, OP_Halt);
sqlite3VdbeJumpHere(v, addr);
/* Bypass the delete logic below if the WHERE loop found zero rows */
addrBypass = sqlite3VdbeAddOp0(v, OP_Goto);
sqlite3VdbeJumpHere(v, addrDelete);
}
/* Delete every item whose key was written to the list during the
** database scan. We have to delete items after the scan is complete
** because deleting an item can change the scan order. */
end = sqlite3VdbeMakeLabel(v);
/* Unless this is a view, open cursors for the table we are
** deleting from and all its indices. If this is a view, then the
** only effect this statement has is to fire the INSTEAD OF
** triggers. */
** triggers.
*/
if( !isView ){
sqlite3OpenTableAndIndices(pParse, pTab, OP_OpenWrite, iTabCur, aToOpen,
&iDataCur, &iIdxCur);
assert( iDataCur==iTabCur );
assert( iIdxCur==iDataCur+1 );
assert( pPk || iDataCur==iTabCur );
assert( pPk || iIdxCur==iDataCur+1 );
}
if( !okOnePass ){
addr = sqlite3VdbeAddOp3(v, OP_RowSetRead, iRowSet, end, regRowid);
}
/* Set up a loop over the rowids/primary-keys that were found in the
** where-clause loop above.
*/
if( okOnePass ){
/* Just one row. Hence the top-of-loop is a no-op */
assert( nKey==nPk ); /* OP_Found will use an unpacked key */
}else if( pPk ){
addrLoop = sqlite3VdbeAddOp1(v, OP_Rewind, iEphCur);
sqlite3VdbeAddOp2(v, OP_RowKey, iEphCur, iKey);
assert( nKey==0 ); /* OP_Found will use a composite key */
}else{
addrLoop = sqlite3VdbeAddOp3(v, OP_RowSetRead, iRowSet, 0, iKey);
assert( nKey==1 );
}
/* 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, regRowid, pVTab, P4_VTAB);
sqlite3VdbeAddOp4(v, OP_VUpdate, 0, 1, iKey, pVTab, P4_VTAB);
sqlite3VdbeChangeP5(v, OE_Abort);
sqlite3MayAbort(pParse);
}else
@@ -516,23 +501,28 @@ void sqlite3DeleteFrom(
{
int count = (pParse->nested==0); /* True to count changes */
sqlite3GenerateRowDelete(pParse, pTab, pTrigger, iDataCur, iIdxCur,
regRowid, 1, count, OE_Default, okOnePass);
iKey, nKey, count, OE_Default, okOnePass);
}
/* End of the delete loop */
if( !okOnePass ){
sqlite3VdbeAddOp2(v, OP_Goto, 0, addr);
}
sqlite3VdbeResolveLabel(v, end);
/* End of the loop over all rowids/primary-keys. */
if( okOnePass ){
sqlite3VdbeJumpHere(v, addrBypass);
}else if( pPk ){
sqlite3VdbeAddOp2(v, OP_Next, iEphCur, addrLoop+1);
sqlite3VdbeJumpHere(v, addrLoop);
}else{
sqlite3VdbeAddOp2(v, OP_Goto, 0, addrLoop);
sqlite3VdbeJumpHere(v, addrLoop);
}
/* Close the cursors open on the table and its indexes. */
if( !isView && !IsVirtual(pTab) ){
sqlite3VdbeAddOp1(v, OP_Close, iDataCur);
if( !pPk ) sqlite3VdbeAddOp1(v, OP_Close, iDataCur);
for(i=0, pIdx=pTab->pIndex; pIdx; i++, pIdx=pIdx->pNext){
sqlite3VdbeAddOp1(v, OP_Close, iIdxCur + i);
}
}
}
} /* End non-truncate path */
/* Update the sqlite_sequence table by storing the content of the
** maximum rowid counter values recorded while inserting into