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: 2013-01-11T16:31:59Z
Lists: pgsql-hackers
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 > 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