Re: Notice lock waits - Mailing list pgsql-hackers

From Haribabu Kommi
Subject Re: Notice lock waits
Date
Msg-id CAJrrPGe=-tSbYooSsLJaQwwM9YHo88G--hAj0naMRuUSEjTAjg@mail.gmail.com
Whole thread Raw
In response to Re: Notice lock waits  (Jeff Janes <jeff.janes@gmail.com>)
List pgsql-hackers


On Fri, Sep 30, 2016 at 3:00 AM, Jeff Janes <jeff.janes@gmail.com> wrote:
On Wed, Sep 28, 2016 at 11:57 PM, Haribabu Kommi <kommi.haribabu@gmail.com> wrote:

Providing the details of lock wait to the client is good. I fell this message
is useful for the cases where User/administrator is trying to perform some
SQL operations.

I also feel that, adding a GUC variable for these logs to show it to user
may not be good. Changing the existing GUC may be better.

I don't think it would be a good idea to refactor the existing GUC (log_lock_waits) to accomplish this.

There would have to be four states, log only, notice only, both log and notice, and neither.  But non-superusers can't be allowed to  change the log flag, only the notice flag.  It is probably possible to implement that, but it seems complicated both to implement, and to explain/document.  I think that adding another GUC is better than greatly complicating an existing one.

Yes, I understood. Changing the existing GUC will make it complex. 

What do you think of Jim Nasby's idea of making a settable level, rather just on or off?

I am not clearly understood, how the settable level works here? Based on log_min_messages
or something, the behavior differs?

The Notification messages are good, If we are going to add this facility only for lock waits, then
a simple GUC is enough. If we are going to enhance the same for other messages, then I prefer
something like log_statement GUC to take some input from user and those messages will be
sent to the user.
 
Regards,
Hari Babu
Fujitsu Australia

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