Re: slow join on postgresql6.5
От | Bruce Momjian |
---|---|
Тема | Re: slow join on postgresql6.5 |
Дата | |
Msg-id | 200004021636.MAA04853@candle.pha.pa.us обсуждение исходный текст |
Ответ на | RE: slow join on postgresql6.5 ("Hiroshi Inoue" <Inoue@tpf.co.jp>) |
Список | pgsql-hackers |
> > >As for NULL,it seems possible to look up NULL keys in a btree index > > >because NULL == NULL for btree indexes. > > >I've wondered why PostgreSQL's planner/executor never looks up > > >indexes for queries using 'IS NULL'. > > > > Unfortunately for the RI MATCH PARTIAL case, NULL is a "wildcard". > > > > Oops I misunderstood NULL. > > Hmm,is the following TODO worth the work ? > * Use index to restrict rows returned by multi-key index when used with > non-consecutive keys or OR clauses, so fewer heap accesses. This is a Vadim item. -- Bruce Momjian | http://www.op.net/~candle pgman@candle.pha.pa.us | (610) 853-3000+ If your life is a hard drive, | 830 Blythe Avenue + Christ can be your backup. | Drexel Hill, Pennsylvania19026
В списке pgsql-hackers по дате отправления: