Hello,
While discussing with the development team, an interesting question came up: in a synchronous streaming replication scenario, with synchronous_commit = remote_apply, will the change be first visible on Standby (replica)? Primary will wait till the change is applied and committed on standby, and hence logically this looks to be correct. But I couldn't find this mentioned explicitly anywhere and hence seeking comments from the community.
Assuming that the answer is yes, potentially the same can happen even with synchronous_commit = remote_write | ON because on the way back to Primary, if the network is slow, there is a chance that Standby may complete applying the change and make it visible to the users.
Would sincerely appreciate if someone can share a documentation/blog link that explains this, if there is one.
Many Thanks!