On 2021-Jul-16, Greg Nancarrow wrote: > On Fri, Jul 16, 2021 at 3:50 PM Amit Kapila <amit.kapil...@gmail.com> wrote: > > > > I am not so sure about different filters for old and new rows but it > > makes sense to by default apply the filter to both old and new rows. > > Then also provide a way for user to specify if the filter can be > > specified to just old or new row. > > I'm having some doubts and concerns about what is being suggested.
Yeah. I think the idea that some updates fail to reach the replica, leaving the downstream database in a different state than it would be if those updates had reached it, is unsettling. It makes me wish we raised an error at UPDATE time if both rows would not pass the filter test in the same way -- that is, if the old row passes the filter, then the new row must be a pass as well. Maybe a second option is to have replication change any UPDATE into either an INSERT or a DELETE, if the old or the new row do not pass the filter, respectively. That way, the databases would remain consistent. -- Álvaro Herrera 39°49'30"S 73°17'W — https://www.EnterpriseDB.com/ "You're _really_ hosed if the person doing the hiring doesn't understand relational systems: you end up with a whole raft of programmers, none of whom has had a Date with the clue stick." (Andrew Sullivan)
