From: pgsql-hackers-ow...@postgresql.org > [mailto:pgsql-hackers-ow...@postgresql.org] On Behalf Of Craig Ringer > On 13 April 2017 at 14:59, Tsunakawa, Takayuki > <tsunakawa.ta...@jp.fujitsu.com> wrote: > > > 2. Make transaction_read_only GUC_REPORT This is to avoid the added > > round-trip by SHOW command. It also benefits client apps that want to > know when the server gets promoted? And this may simplify the libpq code. > > I don't understand yet why we need to provide this feature for older servers > by using SHOW. Those who are already using <= 9.6 in production completed > the system or application, and their business is running. Why would they > want to just replace libpq and use this feature? > > I think "transaction_read_only" is a bit confusing for something we're > expecting to change under us. > > To me, a "read only" xact is one created with > > BEGIN READ ONLY TRANSACTION; > > .... which I would not expect to become read/write under me, since I > explicitly asked for read-only. > > It's more like "session read only" that we're interested in IMO.
Are you suggest thating we provide a GUC_REPORT read-only variable "session_read_only" and the libpq should use it? Anyway, I added this item in the PostgreSQL 10 Open Items page under "Design Decisions to Recheck Mid-Beta". I'm willing to submit a patch for PG10. Regards Takayuki Tsunakawa -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
