Re: Correct query to check streaming replication lag

On Fri, Jan 17, 2014 at 5:31 PM, Granthana Biswas <granthana(at)zedo(dot)com>wrote:

>
>
> Thank you Sameer for your reply. Is there any other query that would help
> get exact replication lag?
>
>
You 2nd Query is the most accurate you can get.

> 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.
>>
>> You can get lags in terms of bytes (and I have always believed that
makes more sense).

May I ask, why are you looking for this info? Is it purely monitoring?

Regards
Sameer
Ashnik Pte Ltd.