Re: WIP: explain analyze with 'rows' but not timing

Pavel Stehule <pavel.stehule@gmail.com>

From: Pavel Stehule <pavel.stehule@gmail.com>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Tomas Vondra <tv@fuzzy.cz>, pgsql-hackers@postgresql.org
Date: 2011-12-24T05:31:31Z
Lists: pgsql-hackers
2011/12/23 Tom Lane <tgl@sss.pgh.pa.us>:
> Pavel Stehule <pavel.stehule@gmail.com> writes:
>> 2011/12/23 Tom Lane <tgl@sss.pgh.pa.us>:
>>> Tomas Vondra <tv@fuzzy.cz> writes:
>>>> The motivation for this patch was that collection timing data often
>>>> causes performance issues and in some cases it's not needed. But is this
>>>> true for row counts?
>
>>> Perhaps more to the point, is there a use case for collecting timing
>>> data without row counts?  I find it hard to visualize a valid reason.
>
>> yes - a searching of bad prediction
>
> No, because timing alone proves nothing at all.  The machine could just
> have been overloaded.

sorry, I didn't understand to question.

Using only time is not practical

Regards

Pavel

>
>                        regards, tom lane