On 12/3/23 18:52, Tomas Vondra wrote: > ... > > Some time ago I floated the idea of maybe "queuing" the sequence changes > and only replay them on the next commit, somehow. But we did ran into > problems with which snapshot to use, that I didn't know how to solve. > Maybe we should try again. The idea is we'd queue the non-transactional > changes somewhere (can't be in the transaction, because we must keep > them even if it aborts), and then "inject" them into the next commit. > That'd mean we wouldn't do the separate start/abort for each change. >
Another idea is that maybe we could somehow inform ReorderBuffer whether the output plugin even is interested in sequences. That'd help with cases where we don't even want/need to replicate sequences, e.g. because the publication does not specify (publish=sequence). What happens now in that case is we call ReorderBufferQueueSequence(), it does the whole dance with starting/aborting the transaction, calls rb->sequence() which just does "meh" and doesn't do anything. Maybe we could just short-circuit this by asking the output plugin somehow. In an extreme case the plugin may not even specify the sequence callbacks, and we're still doing all of this. regards -- Tomas Vondra EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company
