On Sat, Aug 6, 2016 at 3:00 AM, Jeff Janes <jeff.ja...@gmail.com> wrote:
> One time too many, I ran some minor change using psql on a production > server and was wondering why it was taking so much longer than it did > on the test server. Only to discover, after messing around with > opening new windows and running queries against pg_stat_activity and > pg_locks and so on, that it was waiting for a lock. > > So I created a new guc, notice_lock_waits, which acts like > log_lock_waits but sends the message as NOTICE so it will show up on > interactive connections like psql. > > I turn it on in my .psqlrc, as it doesn't make much sense for me to > turn it on in non-interactive sessions. > > A general facility for promoting selected LOG messages to NOTICE would > be nice, but I don't know how to design or implement that. This is > much easier, and I find it quite useful. > > I have it PGC_SUSET because it does send some tiny amount of > information about the blocking process (the PID) to the blocked > process. That is probably too paranoid, because the PID can be seen > by anyone in the pg_locks table anyway. > > Do you think this is useful and generally implemented in the correct > way? If so, I'll try to write some sgml documentation for it. > 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 am not sure whether it really beneficial in providing all LOG as NOTICE messages with a generic framework, it may be unnecessary overhead for some users, I am not 100% sure. Regards, Hari Babu Fujitsu Australia
