On 04 April 2014 18:09, Joshua Yanovski Wrote: > The counter would be updated only by VACUUM, which would perform the > same computation performed by the COUNT operation but add it > permanently to counter just before it set the visible_map bit to 1 (I > am not certain whether this would require unusual changes to WAL > replay or not).
I think there is one more disadvantages with this (or maybe I have missed something): User may not use count(*) or may use just once after creating new kind of index proposed but VACUUM will have to keep performing operation equivalent to iterative count(*), which might degrade performance for VACUUM. Thanks and Regards, Kumar Rajeev Rastogi -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers