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Update the spellfix virtual table to optimize queries of the form "SELECT ... FROM tbl WHERE rowid=?".

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FossilOrigin-Name: a0ba55ff0596c5f15e9cdb254c68ef50df2dfaad
This commit is contained in:
dan
2014-01-22 17:43:16 +00:00
parent 8561c81ed6
commit a8a0617e06
4 changed files with 81 additions and 12 deletions
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32
ext/misc/spellfix.c
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@ -2051,6 +2051,7 @@ static int spellfix1Close(sqlite3_vtab_cursor *cur){
** (D) scope = $scope
** (E) distance < $distance
** (F) distance <= $distance
** (G) rowid = $rowid
**
** The plan number is a bit mask formed with these bits:
**
@ -2060,8 +2061,9 @@ static int spellfix1Close(sqlite3_vtab_cursor *cur){
** 0x08 (D) is found
** 0x10 (E) is found
** 0x20 (F) is found
** 0x40 (G) is found
**
** filter.argv[*] values contains $str, $langid, $top, and $scope,
** filter.argv[*] values contains $str, $langid, $top, $scope and $rowid
** if specified and in that order.
*/
static int spellfix1BestIndex(sqlite3_vtab *tab, sqlite3_index_info *pIdxInfo){
@ -2070,6 +2072,7 @@ static int spellfix1BestIndex(sqlite3_vtab *tab, sqlite3_index_info *pIdxInfo){
int iTopTerm = -1;
int iScopeTerm = -1;
int iDistTerm = -1;
int iRowidTerm = -1;
int i;
const struct sqlite3_index_constraint *pConstraint;
pConstraint = pIdxInfo->aConstraint;
@ -2122,6 +2125,15 @@ static int spellfix1BestIndex(sqlite3_vtab *tab, sqlite3_index_info *pIdxInfo){
iPlan |= pConstraint->op==SQLITE_INDEX_CONSTRAINT_LT ? 16 : 32;
iDistTerm = i;
}
/* Terms of the form: distance < $dist or distance <= $dist */
if( (iPlan & 64)==0
&& pConstraint->iColumn<0
&& pConstraint->op==SQLITE_INDEX_CONSTRAINT_EQ
){
iPlan |= 64;
iRowidTerm = i;
}
}
if( iPlan&1 ){
int idx = 2;
@ -2149,6 +2161,11 @@ static int spellfix1BestIndex(sqlite3_vtab *tab, sqlite3_index_info *pIdxInfo){
pIdxInfo->aConstraintUsage[iDistTerm].omit = 1;
}
pIdxInfo->estimatedCost = 1e5;
}else if( (iPlan & 64) ){
pIdxInfo->idxNum = 64;
pIdxInfo->aConstraintUsage[iRowidTerm].argvIndex = 1;
pIdxInfo->aConstraintUsage[iRowidTerm].omit = 1;
pIdxInfo->estimatedCost = 5;
}else{
pIdxInfo->idxNum = 0;
pIdxInfo->estimatedCost = 1e50;
@ -2465,16 +2482,23 @@ static int spellfix1FilterForFullScan(
int argc,
sqlite3_value **argv
){
int rc;
int rc = SQLITE_OK;
char *zSql;
spellfix1_vtab *pVTab = pCur->pVTab;
spellfix1ResetCursor(pCur);
assert( idxNum==0 || idxNum==64 );
zSql = sqlite3_mprintf(
"SELECT word, rank, NULL, langid, id FROM \"%w\".\"%w_vocab\"",
pVTab->zDbName, pVTab->zTableName);
"SELECT word, rank, NULL, langid, id FROM \"%w\".\"%w_vocab\"%s",
pVTab->zDbName, pVTab->zTableName,
((idxNum & 64) ? " WHERE rowid=?" : "")
);
if( zSql==0 ) return SQLITE_NOMEM;
rc = sqlite3_prepare_v2(pVTab->db, zSql, -1, &pCur->pFullScan, 0);
sqlite3_free(zSql);
if( rc==SQLITE_OK && (idxNum & 64) ){
assert( argc==1 );
rc = sqlite3_bind_value(pCur->pFullScan, 1, argv[0]);
}
pCur->nRow = pCur->iRow = 0;
if( rc==SQLITE_OK ){
rc = sqlite3_step(pCur->pFullScan);