| From: | Adriano Lange <alange0001(at)gmail(dot)com> |
|---|---|
| To: | Andres Freund <andres(at)2ndquadrant(dot)com> |
| Cc: | pgsql-hackers(at)postgresql(dot)org |
| Subject: | Re: SDP query optimizer |
| Date: | 2013-03-23 17:51:18 |
| Message-ID: | 514DEB96.1010806@gmail.com |
| Views: | Raw Message | Whole Thread | Download mbox | Resend email |
| Thread: | |
| Lists: | pgsql-hackers |
On 23-03-2013 10:15, Andres Freund wrote:
> I just want to mention that unless you skew the statistics for the individual
> tables from their empty/default state this mostly measures a pretty degenerate
> case where optima are very rare and not very differentiated. Thats a useful
> thing to test, but not to have as the target to optimize for.
> So it might be interesting to run that thing with some table
> stats/contents stats set up.
Yes, the search space obtained from this experiment may be very simpler
than a real case. Beyond this experiment, I can construct classical
queries used to evaluate this kind of algorithm, as stars, cliques,
chains and cycles. Beyond these queries I have no idea how can I further
test it.
Regards,
Adriano Lange
| From | Date | Subject | |
|---|---|---|---|
| Next Message | Tom Lane | 2013-03-23 18:34:09 | Re: Request for Patch Feedback: Lag & Lead Window Functions Can Ignore Nulls |
| Previous Message | Nicholas White | 2013-03-23 17:00:25 | Request for Patch Feedback: Lag & Lead Window Functions Can Ignore Nulls |