From: | Bruce Momjian <maillist(at)candle(dot)pha(dot)pa(dot)us> |
---|---|
To: | pjw(at)rhyme(dot)com(dot)au |
Cc: | pgsql-ports(at)postgreSQL(dot)org |
Subject: | Re: [PORTS] Port Bug Report: Suggestion: Allow users to specify optimizer hints or strategies. |
Date: | 1999-04-13 14:40:15 |
Message-ID: | 199904131440.KAA13884@candle.pha.pa.us |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-ports |
> Given the various complexities of the optimizer, would there be
> any way of allowing developers to specify strategy, or give
> hints. This is allowed in Dec (now Oracle) RDB, and in some
> fashion in both SQL/Server and Sybase.
>
> The sorts of things that might be desirable are: which index to
> join on and the order of joining the tables.
>
> Digital Equipment Corp used to maintain that the optimizer should
> know best, and that developers make more mistakes, and that is
> true. But an experienced DBA, along with details of common
> transactions, can almost always do better than an optimizer.
Usually hand-tuning joins is a symtom of a bad optimizer. Rdb never had
a world-class optimizer, as far as I remember.
--
Bruce Momjian | http://www.op.net/~candle
maillist(at)candle(dot)pha(dot)pa(dot)us | (610) 853-3000
+ If your life is a hard drive, | 830 Blythe Avenue
+ Christ can be your backup. | Drexel Hill, Pennsylvania 19026
From | Date | Subject | |
---|---|---|---|
Next Message | Bruce Momjian | 1999-04-13 14:43:21 | Re: [PORTS] Port Bug Report: Tables, indexes...really owned by postgres are ghosted by other user |
Previous Message | Unprivileged user | 1999-04-13 13:47:44 | Port Bug Report: |