Thank you Sameer for your reply. Is there any other query that would help get exact replication lag?
Regards, Granthana Regards, Granthana On Fri, Jan 17, 2014 at 2:46 PM, Sameer Kumar <sameer.ku...@ashnik.com>wrote: > > On Tue, Jan 14, 2014 at 2:31 PM, Granthana Biswas <granth...@zedo.com>wrote: > >> Can anyone please tell me which of the following is the correct >> replication lag query to find streaming replication lag in seconds? >> >> IMHO none is 'correct'. :-) > > 1. SELECT extract(seconds from (now() - pg_last_xact_replay_timestamp())) >> AS time_lag; >> >> This is the difference between now and last replayed log. What if the > last transaction on master has happened a few minutes ago? > > >> 2. SELECT CASE WHEN pg_last_xlog_receive_location() = >> pg_last_xlog_replay_location() THEN 0 ELSE EXTRACT (EPOCH FROM now() - >> pg_last_xact_replay_timestamp()) END AS log_delay; >> > > For reason same as above, this won't be exact but the most accurate you > can get. > > Best Regards, > *Sameer Kumar | Database Consultant* > > *ASHNIK PTE. LTD.*101 Cecil Street, #11-11 Tong Eng Building, Singapore > 069533 > M : *+65 8110 0350 <%2B65%208110%200350>* T: +65 6438 3504 | > www.ashnik.com > www.facebook.com/ashnikbiz | www.twitter.com/ashnikbiz > > [image: email patch] > > This email may contain confidential, privileged or copyright material and > is solely for the use of the intended recipient(s). >
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