On Wednesday, March 22, 2017 2:17:27 PM EDT Jaime Casanova wrote: > On 18 March 2017 at 14:01, Elvis Pranskevichus <elpr...@gmail.com> wrote: > > On Saturday, March 18, 2017 3:33:16 AM EDT Michael Paquier wrote: > >> Why adding a good chunk of code instead of using > >> pg_is_in_recovery(), > >> which switches to false once a server exits recovery? > > > > That requires polling the database continuously, which may not be > > possible or desirable. > > > > My main motivation here is to gain the ability to manage a pool of > > connections in asyncpg efficiently. A part of the connection > > release > > protocol is "UNLISTEN *;", which the server in Hot Standby would > > fail to process. Polling the database for pg_is_in_recovery() is > > not feasible in this case, unfortunately. > > Sorry, i still don't understand the motivation for this. > At one point you're going to poll for the value of the GUC in > pg_settings, no? Or how are you going to know the current value of > the GUC that makes it different to just poll for pg_is_in_recovery()?
It is marked as GUC_REPORT and is reported by the server on connection and on every change: https://www.postgresql.org/docs/current/static/protocol-flow.html#PROTOCOL-ASYNC Elvis -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
