Re: ToDo: log plans of cancelled queries

Pavel Stehule <pavel.stehule@gmail.com>

From: Pavel Stehule <pavel.stehule@gmail.com>
To: Stephen Frost <sfrost@snowman.net>
Cc: Tom Lane <tgl@sss.pgh.pa.us>, Simon Riggs <simon@2ndquadrant.com>, Alvaro Herrera <alvherre@2ndquadrant.com>, PostgreSQL Hackers <pgsql-hackers@postgresql.org>
Date: 2013-01-11T16:34:01Z
Lists: pgsql-hackers
2013/1/11 Pavel Stehule <pavel.stehule@gmail.com>:
> 2013/1/11 Stephen Frost <sfrost@snowman.net>:
>> * Tom Lane (tgl@sss.pgh.pa.us) wrote:
>>> Simon Riggs <simon@2ndQuadrant.com> writes:
>>> > An even better feature would be to be able to send a signal to a
>>> > running query to log its currently executing plan. That way you can
>>> > ask "Why so slow?" before deciding to kill it.
>>>
>>> That could conceivably work.  At least it wouldn't require running
>>> EXPLAIN in a failed transaction.
>>
>> I like this idea, in general, also.  Taking that to the next level would
>> be figuring out how you can do the same kind of thing through an
>> interactive psql session where the user running the query doesn't need
>> access to the database server or PG log files...
>>
>
> this is simple - it can be printed via elog(WARNING, ...) to original console

theoretically we can show current state via EXPLAIN ANALYSE result

>
>> We can send a 'cancel query', how about a 'report on query' which
>> returns the plan and perhaps whatever other stats are easily available?
>
> there is only one question - that POSIX signal we can use?
>
> Pavel
>
>>
>>         Thanks,
>>
>>                 Stephen