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Delete PRIMARY KEY index entries last. Only construct the unique prefix of

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an index key when deleting entries from an index.

FossilOrigin-Name: 0e56ba69f0fcd12a5166c32f6e4eacdcc29fba04
This commit is contained in:
drh
2013-10-24 14:16:10 +00:00
parent acbbc5ba36
commit 9eade087da
6 changed files with 46 additions and 29 deletions
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46
src/delete.c
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@@ -134,7 +134,7 @@ Expr *sqlite3LimitWhere(
ExprList *pOrderBy, /* The ORDER BY clause. May be null */
Expr *pLimit, /* The LIMIT clause. May be null */
Expr *pOffset, /* The OFFSET clause. May be null */
char *zStmtType /* Either DELETE or UPDATE. For error messages. */
char *zStmtType /* Either DELETE or UPDATE. For err msgs. */
){
Expr *pWhereRowid = NULL; /* WHERE rowid .. */
Expr *pInClause = NULL; /* WHERE rowid IN ( select ) */
@@ -209,7 +209,8 @@ limit_where_cleanup_2:
sqlite3ExprDelete(pParse->db, pOffset);
return 0;
}
#endif /* defined(SQLITE_ENABLE_UPDATE_DELETE_LIMIT) && !defined(SQLITE_OMIT_SUBQUERY) */
#endif /* defined(SQLITE_ENABLE_UPDATE_DELETE_LIMIT) */
/* && !defined(SQLITE_OMIT_SUBQUERY) */
/*
** Generate code for a DELETE FROM statement.
@@ -408,7 +409,8 @@ void sqlite3DeleteFrom(
#endif
{
int count = (pParse->nested==0); /* True to count changes */
sqlite3GenerateRowDelete(pParse, pTab, iCur, iRowid, count, pTrigger, OE_Default);
sqlite3GenerateRowDelete(pParse, pTab, iCur, iRowid, count,
pTrigger, OE_Default);
}
/* End of the delete loop */
@@ -466,10 +468,10 @@ delete_from_cleanup:
** These are the requirements:
**
** 1. A read/write cursor pointing to pTab, the table containing the row
** to be deleted, must be opened as cursor number $iCur.
** to be deleted, must be opened as cursor number iCur.
**
** 2. Read/write cursors for all indices of pTab must be open as
** cursor number base+i for the i-th index.
** cursor number iCur+i for the i-th index.
**
** 3. The record number of the row to be deleted must be stored in
** memory cell iRowid.
@@ -575,13 +577,17 @@ void sqlite3GenerateRowDelete(
** These are the requirements:
**
** 1. A read/write cursor pointing to pTab, the table containing the row
** to be deleted, must be opened as cursor number "iCur".
** to be deleted, must be opened as cursor number "iCur". For
** WITHOUT ROWID tables that do not have a main table, the iCur
** cursor is unused.
**
** 2. Read/write cursors for all indices of pTab must be open as
** cursor number iCur+i for the i-th index.
**
** 3. The "iCur" cursor must be pointing to the row that is to be
** deleted.
** deleted. Or, for WITHOUT ROWID tables, the iCur+i cursor for
** the PRIMARY KEY index must be pointing to the row to that is
** to be deleted.
*/
void sqlite3GenerateRowIndexDelete(
Parse *pParse, /* Parsing and code generating context */
@@ -589,22 +595,32 @@ void sqlite3GenerateRowIndexDelete(
int iCur, /* Cursor number for the table */
int *aRegIdx /* Only delete if aRegIdx!=0 && aRegIdx[i]>0 */
){
int i;
int i, iPk = 0;
Index *pIdx;
int r1;
int iPartIdxLabel;
Vdbe *v = pParse->pVdbe;
Index *pPk;
pPk = sqlite3PrimaryKeyIndex(pTab);
for(i=1, pIdx=pTab->pIndex; pIdx; i++, pIdx=pIdx->pNext){
if( aRegIdx!=0 && aRegIdx[i-1]==0 ) continue;
r1 = sqlite3GenerateIndexKey(pParse, pIdx, iCur, 0, 0, &iPartIdxLabel);
sqlite3VdbeAddOp3(v, OP_IdxDelete, iCur+i, r1, pIdx->nKeyCol+1);
if( pIdx==pPk ){ iPk = iCur+i; continue; }
r1 = sqlite3GenerateIndexKey(pParse, pIdx, iCur, 0, 1, &iPartIdxLabel);
sqlite3VdbeAddOp3(v, OP_IdxDelete, iCur+i, r1,
pIdx->uniqNotNull ? pIdx->nKeyCol : pIdx->nColumn);
sqlite3VdbeResolveLabel(v, iPartIdxLabel);
}
if( iPk ){
r1 = sqlite3GenerateIndexKey(pParse, pPk, iCur, 0, 1, &iPartIdxLabel);
sqlite3VdbeAddOp3(v, OP_IdxDelete, iPk, r1,
pPk->uniqNotNull ? pPk->nKeyCol : pPk->nColumn);
sqlite3VdbeResolveLabel(v, iPartIdxLabel);
}
}
/*
** Generate code that will assemble an index key and put it in register
** Generate code that will assemble an index key and stores it in register
** regOut. The key with be for index pIdx which is an index on pTab.
** iCur is the index of a cursor open on the pTab table and pointing to
** the entry that needs indexing.
@@ -625,8 +641,8 @@ int sqlite3GenerateIndexKey(
Parse *pParse, /* Parsing context */
Index *pIdx, /* The index for which to generate a key */
int iCur, /* Cursor number for the pIdx->pTable table */
int regOut, /* Write the new index key to this register */
int doMakeRec, /* Run the OP_MakeRecord instruction if true */
int regOut, /* Put the new key into this register if not 0 */
int prefixOnly, /* Compute only a unique prefix of the key */
int *piPartIdxLabel /* OUT: Jump to this label to skip partial index */
){
Vdbe *v = pParse->pVdbe;
@@ -646,7 +662,7 @@ int sqlite3GenerateIndexKey(
*piPartIdxLabel = 0;
}
}
nCol = pIdx->nColumn;
nCol = (prefixOnly && pIdx->uniqNotNull) ? pIdx->nKeyCol : pIdx->nColumn;
regBase = sqlite3GetTempRange(pParse, nCol);
pPk = HasRowid(pTab) ? 0 : sqlite3PrimaryKeyIndex(pTab);
for(j=0; j<nCol; j++){
@@ -659,7 +675,7 @@ int sqlite3GenerateIndexKey(
sqlite3ColumnDefault(v, pTab, idx, -1);
}
}
if( doMakeRec ){
if( regOut ){
const char *zAff;
if( pTab->pSelect
|| OptimizationDisabled(pParse->db, SQLITE_IdxRealAsInt)