Re: Is a better way to have the same result of this
| От | Vernon Wu |
|---|---|
| Тема | Re: Is a better way to have the same result of this |
| Дата | |
| Msg-id | 5A6KF0NHNMGEJG7XRYWL1X8X8.3defbde5@kimiko обсуждение исходный текст |
| Ответы |
Re: Is a better way to have the same result of this
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| Список | pgsql-performance |
Tomasz, I am under the impression that a primary key field is automically as a unique index. It seems to be correct after I verifyit with the page http://www.commandprompt.com/ppbook/index.lxp?lxpwrap=c13329%2ehtm#CREATINGANINDEX Thanks for bringing up the question. Vernon 12/5/2002 12:35:36 PM, Tomasz Myrta <jasiek@klaster.net> wrote: >Vernon Wu wrote: > >> The personid is a foreign key in the block table, and the the userid >> is the key of the profile table. So, both are indexed >> by nature (if I don't make a mistake). > >What kind of nature? Did you create indexes for these fields? Postgres >doesn't create indexes by itself - even if field is a primary key. You >have to do it on your own. I think also, that Postgres doesn't use index >for tables having less then 200 rows - sequence scan is faster. >Regards, >Tomasz Myrta > > >
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