On Sat, Dec 28, 2019 at 1:56 PM Pierre Ducroquet <p.p...@pinaraf.info> wrote: > > Thank you for your comments. > Attached to this email is a patch with better comments regarding the > XLogSendLogical change.
Arguably the first test to compare to InvalidXLogRecPtr is unneeded, as any value of EndRecPtr is greater or equal than that value. It will only save at best 1 GetFlushRecPtr() per walsender process lifetime, so I'm not sure it's worth arguing about it. Other than that I still think that it's a straightforward optimization that brings nice speedup, and I don't see any problem with this patch. I think that given the time of the year you should create a commitfest entry for this patch to make sure it won't be forgotten (and obviously I'll mark it as RFC, unless someone objects by then). > We've spent quite some time yesterday benching it again, this time with > changes that must be fully processed by the decoder. The speed-up is obviously > much smaller, we are only ~5% faster than without the patch. I'm assuming that it's benchmarking done with multiple logical slots? Anyway, a 5% speedup in the case that this patch is not aimed to optimize is quite nice!
