From: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> |
---|---|
To: | "Simon Riggs" <simon(at)2ndquadrant(dot)com> |
Cc: | "Peter Eisentraut" <peter_e(at)gmx(dot)net>, pgsql-hackers(at)postgresql(dot)org, "Kelly Burkhart" <kelly(dot)burkhart(at)gmail(dot)com>, "Evgeny Gridasov" <eugrid(at)fpm(dot)kubsu(dot)ru>, pgsql-performance(at)postgresql(dot)org |
Subject: | Re: [HACKERS] EXPLAIN ANALYZE on 8.2 |
Date: | 2006-12-19 04:43:00 |
Message-ID: | 10651.1166503380@sss.pgh.pa.us |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-hackers pgsql-performance |
"Simon Riggs" <simon(at)2ndquadrant(dot)com> writes:
> On Fri, 2006-12-15 at 09:56 -0500, Tom Lane wrote:
>> The fundamental problem with it was the assumption that different
>> executions of a plan node will have the same timing. That's not true,
>> in fact not even approximately true.
> It doesn't make sense to me to claim that the timing is so important
> that we cannot do without it, at the same time as saying it isn't even
> approximately true that is highly variable.
Huh? What I said was that successive executions of the same plan node
may take considerably different amounts of time, and the proposed
sampling patch failed to handle that situation with acceptable accuracy.
regards, tom lane
From | Date | Subject | |
---|---|---|---|
Next Message | Tom Lane | 2006-12-19 04:46:55 | Re: effective_cache_size vs units |
Previous Message | Bruce Momjian | 2006-12-19 03:23:59 | Re: pg_restore fails with a custom backup file |
From | Date | Subject | |
---|---|---|---|
Next Message | Tom Lane | 2006-12-19 08:08:56 | Re: Insertion to temp table deteriorating over time |
Previous Message | Steven Flatt | 2006-12-18 23:06:04 | Re: Insertion to temp table deteriorating over time |