| From: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> |
|---|---|
| To: | "Ansley, Michael" <Michael(dot)Ansley(at)intec(dot)co(dot)za> |
| Cc: | pgsql-hackers(at)postgreSQL(dot)org |
| Subject: | Re: [HACKERS] Re: Top N queries and disbursion |
| Date: | 1999-10-08 14:29:46 |
| Message-ID: | 3027.939392986@sss.pgh.pa.us |
| Views: | Raw Message | Whole Thread | Download mbox | Resend email |
| Thread: | |
| Lists: | pgsql-hackers |
"Ansley, Michael" <Michael(dot)Ansley(at)intec(dot)co(dot)za> writes:
> can't we do something similar to what Oracle does, where you can define your
> optimisation to be rule-based, or stats-based. If it's rule based, the
> optimizer looks only at the schema to decide how to optimize. If
> stats-based, then it has a huge amount of information at its disposal to
> determine how to optimise. However, those stats are compiled by something
> like vacuum.
We pretty much do that already; the "rules" are embodied in the default
cost estimates that get used if there's no statistical data from VACUUM.
regards, tom lane
| From | Date | Subject | |
|---|---|---|---|
| Next Message | Thomas Lockhart | 1999-10-08 15:07:33 | Features for next release |
| Previous Message | Tom Lane | 1999-10-08 14:24:43 | Re: [HACKERS] Re: Top N queries and disbursion |