Re: Big 7.4 items
Neil Conway <neilc@samurai.com>
From: Neil Conway <neilc@samurai.com>
To: Jan Wieck <JanWieck@Yahoo.com>
Cc: Bruce Momjian <pgman@candle.pha.pa.us>, shridhar_daithankar@persistent.co.in, PostgreSQL-development <pgsql-hackers@postgresql.org>
Date: 2002-12-13T23:38:33Z
Lists: pgsql-hackers
On Fri, 2002-12-13 at 13:36, Jan Wieck wrote: > But you cannot use the result of such a SELECT to update anything. So > you can only phase out complete read only transaction to the slaves. > Requires support from the application since the load balancing system > cannot know automatically what will be a read only transaction and what > not. Interesting -- SQL contains the concept of "read only" and "read write" transactions (the default is RW). If we implemented that (which shouldn't be too difficult[1]), it might make differentiating between classes of transactions a little easier. Client applications would still need to be modified, but not nearly as much. Does this sound like it's worth doing? [1] -- AFAICS, the only tricky implementation detail is deciding exactly which database operations are "writes". Does nextval() count, for example? Cheers, Neil -- Neil Conway <neilc@samurai.com> || PGP Key ID: DB3C29FC