Re: Throttling WAL inserts when the standby falls behind more than the configured replica_lag_in_bytes

Actually all the WAL insertions are done under a critical section (except few exceptions), that means if you see all the references of XLogInsert(), it is always called under the critical section and that is my main worry about hooking at XLogInsert level.

Got it, understood the concern. But can we document the limitations of the hook and let the hook take care of it? I don't expect an error to be thrown here since we are not planning to allocate memory or make file system calls but instead look at the shared memory state and add delays when required.