Greg Smith wrote: > Josh Berkus wrote: > > > Now that I think about it, the xmin thing really doesn't seem > > conceptually difficult. If the slave just opens a 2nd, special query > > connection back to the master and publishes its oldest xmin there, as > > far as the master is concerned, it's just another query backend. > > Could it be that easy? > > > > Something just like that is in fact already suggested as a workaround in > the Hot Standby manual: > > "The first option is to connect to the primary server and keep a query > active for as long as needed to run queries on the standby. This > guarantees that a WAL cleanup record is never generated and query > conflicts do not occur, as described above. This could be done using > contrib/dblink and pg_sleep(), or via other mechanisms."
I am unclear how you would easily advance the snapshot as each query completes on the slave. -- Bruce Momjian <br...@momjian.us> http://momjian.us EnterpriseDB http://enterprisedb.com PG East: http://www.enterprisedb.com/community/nav-pg-east-2010.do -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
