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Move [7d30880114] to the trunk. Add optimizations to reduce the number of opcodes used for BEFORE UPDATE triggers.

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FossilOrigin-Name: 1b7c5250ccb63182324bfc3f1ea28f17b6db357a
This commit is contained in:
dan
2009-11-27 12:12:34 +00:00
parent 5f18a221a1
commit bb5f168f2e
8 changed files with 174 additions and 58 deletions
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43
src/trigger.c
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@@ -811,7 +811,8 @@ static TriggerPrg *codeRowTrigger(
pProgram->nRef = 1;
pPrg->pTrigger = pTrigger;
pPrg->orconf = orconf;
pPrg->oldmask = 0xffffffff;
pPrg->aColmask[0] = 0xffffffff;
pPrg->aColmask[1] = 0xffffffff;
/* Allocate and populate a new Parse context to use for coding the
** trigger sub-program. */
@@ -872,7 +873,8 @@ static TriggerPrg *codeRowTrigger(
pProgram->nMem = pSubParse->nMem;
pProgram->nCsr = pSubParse->nTab;
pProgram->token = (void *)pTrigger;
pPrg->oldmask = pSubParse->oldmask;
pPrg->aColmask[0] = pSubParse->oldmask;
pPrg->aColmask[1] = pSubParse->newmask;
sqlite3VdbeDelete(v);
}
@@ -1032,28 +1034,36 @@ void sqlite3CodeRowTrigger(
}
/*
** Triggers fired by UPDATE or DELETE statements may access values stored
** in the old.* pseudo-table. This function returns a 32-bit bitmask
** indicating which columns of the old.* table actually are used by
** triggers. This information may be used by the caller to avoid having
** to load the entire old.* record into memory when executing an UPDATE
** or DELETE command.
** Triggers may access values stored in the old.* or new.* pseudo-table.
** This function returns a 32-bit bitmask indicating which columns of the
** old.* or new.* tables actually are used by triggers. This information
** may be used by the caller, for example, to avoid having to load the entire
** old.* record into memory when executing an UPDATE or DELETE command.
**
** Bit 0 of the returned mask is set if the left-most column of the
** table may be accessed using an old.<col> reference. Bit 1 is set if
** table may be accessed using an [old|new].<col> reference. Bit 1 is set if
** the second leftmost column value is required, and so on. If there
** are more than 32 columns in the table, and at least one of the columns
** with an index greater than 32 may be accessed, 0xffffffff is returned.
**
** It is not possible to determine if the old.rowid column is accessed
** by triggers. The caller must always assume that it is.
** It is not possible to determine if the old.rowid or new.rowid column is
** accessed by triggers. The caller must always assume that it is.
**
** There is no equivalent function for new.* references.
** Parameter isNew must be either 1 or 0. If it is 0, then the mask returned
** applies to the old.* table. If 1, the new.* table.
**
** Parameter tr_tm must be a mask with one or both of the TRIGGER_BEFORE
** and TRIGGER_AFTER bits set. Values accessed by BEFORE triggers are only
** included in the returned mask if the TRIGGER_BEFORE bit is set in the
** tr_tm parameter. Similarly, values accessed by AFTER triggers are only
** included in the returned mask if the TRIGGER_AFTER bit is set in tr_tm.
*/
u32 sqlite3TriggerOldmask(
u32 sqlite3TriggerColmask(
Parse *pParse, /* Parse context */
Trigger *pTrigger, /* List of triggers on table pTab */
ExprList *pChanges, /* Changes list for any UPDATE OF triggers */
int isNew, /* 1 for new.* ref mask, 0 for old.* ref mask */
int tr_tm, /* Mask of TRIGGER_BEFORE|TRIGGER_AFTER */
Table *pTab, /* The table to code triggers from */
int orconf /* Default ON CONFLICT policy for trigger steps */
){
@@ -1061,12 +1071,15 @@ u32 sqlite3TriggerOldmask(
u32 mask = 0;
Trigger *p;
assert( isNew==1 || isNew==0 );
for(p=pTrigger; p; p=p->pNext){
if( p->op==op && checkColumnOverlap(p->pColumns,pChanges) ){
if( p->op==op && (tr_tm&p->tr_tm)
&& checkColumnOverlap(p->pColumns,pChanges)
){
TriggerPrg *pPrg;
pPrg = getRowTrigger(pParse, p, pTab, orconf);
if( pPrg ){
mask |= pPrg->oldmask;
mask |= pPrg->aColmask[isNew];
}
}
}