Re: TODO request: log_long_transaction - Mailing list pgsql-hackers

From Robert Haas
Subject Re: TODO request: log_long_transaction
Date
Msg-id CA+TgmoaO8-2KbAOzJ5kOqmu2JGNZzvhU6HyzivgH1fxvWv_i5w@mail.gmail.com
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In response to Re: TODO request: log_long_transaction  (Michael Banck <michael.banck@credativ.de>)
Responses Re: TODO request: log_long_transaction  (Kevin Grittner <kgrittn@ymail.com>)
List pgsql-hackers
You should add this patch here, so it doesn't get forgotten:

https://commitfest.postgresql.org/action/commitfest_view/open

On Fri, Nov 7, 2014 at 2:19 PM, Michael Banck <michael.banck@credativ.de> wrote:
> 1. Should this log when the duration is exceeded (like log_lock_waits),
> or on commit? I guess the latter, cause log_lock_waits is kinda an
> offshoot from the deadlock detector, and other things don't work in a
> similar fashion and/or this might be quite tricky and a non-starter.

Either could be useful.  I'm guessing Josh had the latter in mind.

> 2. It would be quite nice to log long-running idle-in-transaction (i.e.
> transactions which have been idle for a long time, not necessarily long
> transactions which are idle every now and then), but see 1.

I agree.  You could implement this by setting a timeout when going
idle in transaction.

> 3. Should long transactions which are rolled back be logged as well?

Yes.

> 4. We log the statement when exceeding log_min_duration_statement, but
> for transactions, that does not make a lot of sense, or should the last
> statement be logged?  I don't think that would be particularly useful.

This is a potentially serious problem with this whole idea, and the
idea in #2.  You can log that it happened, but without some idea of
what it did, it's probably not going to be too useful.

-- 
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company



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