On Thu, Jul 23, 2020 at 12:11 PM Soumyadeep Chakraborty <soumyadeep2...@gmail.com> wrote: > In the read-only level I was suggesting, I wasn't suggesting that we > stop WAL flushes, in fact we should flush the WAL before we mark the > system as read-only. Once the system declares itself as read-only, it > will not perform any more on-disk changes; It may perform all the > flushes it needs as a part of the read-only request handling.
I think that's already how the patch works, or at least how it should work. You stop new writes, flush any existing WAL, and then declare the system read-only. That can all be done quickly. > What I am saying is it doesn't have to be just the queries. I think we > can cater to all the other use cases simply by forcing a checkpoint > before marking the system as read-only. But that part can't, which means that if we did that, it would break the feature for the originally intended use case. I'm not on board with that. -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company
