Probably you will find pg_last_xact_replay_timestamp() interesting. It returns the timestamp of the last transaction (when the transaction was commited) that was replayed on slave. http://www.postgresql.org/docs/9.1/static/functions-admin.html#FUNCTIONS-RECOVERY-INFO-TABLE On Wed, Mar 14, 2012 at 9:47 PM, David Fennell <david.fennell@xxxxxxxxxxxxxx> wrote: > Hi All, > > I hope this is the correct mailing list to ask this question. > > We are setting up a system using postgresql 9.1 and streaming replication to > copy reference data from a single central location to several remote sites. > The database changes will come in clumps with long periods of no activity in > between. I would like to add some kind of programmatic hook to tell us that > new changes have been received from central so that we can trigger messages > to be sent out to devices on the site that may require updates of their data > so that I don't have to rely on polling the database(s). > > Is there any way to hook at this point? Even if it didn't tell exactly what > had changed, just that a particular database or table had been modified that > would be perfect. I don't mind what language is required either. > > I found reference to wal_sender and wal_receiver hooks which sounds very > close to what I need, but I suspect that wal_receiver is processed before > the data is applied to the database and I would like a hook after the > database has been updated. > > I am assuming that normal triggers cannot be used on a replicated database? > Can someone confirm or deny this? > > Thanks in advance. > > Dave Fennell -- Sergey Konoplev Blog: http://gray-hemp.blogspot.com LinkedIn: http://ru.linkedin.com/in/grayhemp JID/GTalk: gray.ru@xxxxxxxxx Skype: gray-hemp -- Sent via pgsql-admin mailing list (pgsql-admin@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-admin
