Re: four minor proposals for 9.5

On Tue, Apr 8, 2014 at 9:07 PM, Pavel Stehule <pavel(dot)stehule(at)gmail(dot)com> wrote:
> 2014-04-08 6:27 GMT+02:00 Amit Kapila <amit(dot)kapila16(at)gmail(dot)com>:
>> So do you want to just print lock time for error'd statements, won't
>> it better to
>> do it for non-error'd statements as well or rather I feel it can be more
>> useful
>> for non-error statements? Do we already have some easy way to get
>> wait-time
>> for non-error statements?
>
>
> There are two points:
>
> a) we have no a some infrastructure how to glue some specific info to any
> query other than log_line_prefix.

Can't we do that by using log_duration and log_min_duration_statement?
For Example, if I enable these parameters, below is the log:

LOG: duration: 343.000 ms statement: create table t1(c1 int);

> And I have no any idea, how and what
> implement better. And I don't think so any new infrastructure (mechanism) is
> necessary. log_line_prefix increase log size, but it is very well parseable
> - splunk and similar sw has no problem with it.

One thing that could happen if we implement total lock time at
log_line_prefix is that if user enables log_lock_waits, then it will start
printing duration for each lock wait time, not sure again it depends on
implementation.

> b) lock time can be interesting on error statements too - for example - you
> can cancel locked queries - so you would to see a lock time and duration for
> cancelled queries. So this implementation can be sensible too.

Agreed, I just said it will be quite useful for non-error'd long running
statements as well, so it might be good idea to see if we can implement
it for successful statements as well.

With Regards,
Amit Kapila.
EnterpriseDB: http://www.enterprisedb.com