Re: [GENERAL] hash taboo?
От | Bruce Momjian |
---|---|
Тема | Re: [GENERAL] hash taboo? |
Дата | |
Msg-id | 199912180324.WAA03818@candle.pha.pa.us обсуждение исходный текст |
Ответ на | hash taboo? (admin <admin@wtbwts.com>) |
Ответы |
Re: [GENERAL] hash taboo?
|
Список | pgsql-general |
Run some performace tests and let us know. > I've been reading the postgresql manual and I find there is very little > discussion about hash compared to btree. Most of the focus seems to be on > using btree indices even that the default for 'create index' is btree > also. From the documentation, it seems the only difference between either > searching method is that btree can be used with multiple operators whilst > hash can only be used with '='. Furthermore, hash seems to be contained in > memory, so should be limited to small queries or, in my case, queries > using limit (without using sort which would need to retrieve the entire > data anyways). > > My conclusion is that if I can live with just using '=' and using slightly > more memory, I should be using hash. Unfortunately, there is very little > sign in the documentation that I should be using hash at all. Perhaps I > have missed something important. > > If someone could help me make a more rational decision on using searching > methods, I'd appreciate. > > Thanks in advance, > Marc > > > ************ > > -- Bruce Momjian | http://www.op.net/~candle maillist@candle.pha.pa.us | (610) 853-3000 + If your life is a hard drive, | 830 Blythe Avenue + Christ can be your backup. | Drexel Hill, Pennsylvania 19026
В списке pgsql-general по дате отправления: