Hi, On 2021-06-11 13:15:11 -0400, Robert Haas wrote: > On Fri, Jun 11, 2021 at 2:23 AM Jeff Davis <pg...@j-davis.com> wrote: > > * The comment acknowledges that a user might expect an error in that > > case; but doesn't really address why the user would expect an error, > > and why it's OK to violate that expectation. > > This code was written by Andres, so he'd be the best person to comment > on it, but it seems to me that the comment does explain this, and that > it's basically the same explanation as what Amit said. If the client > doesn't have to do anything for a certain range of WAL and just > acknowledges it, it would under your proposal have to also durably > record that it had chosen to do nothing, which might cause extra > fsyncs, potentially lots of extra fsyncs if this happens frequently > e.g. because most tables are filtered out and the replicated ones are > only modified occasionally.
Yes, that's the motivation. > I'm not sure that it would be a good trade-off to have a tighter > sanity check at the expense of adding that overhead. Especially because it very well might break existing working setups... Greetings, Andres Freund
