Andres Freund <and...@anarazel.de> writes: > On 2018-01-12 17:24:54 -0500, Tom Lane wrote: >> Andres Freund <and...@anarazel.de> writes: >>> Right. I wonder if it be reasonable to move that to a page's header >>> instead of individual records? To avoid torn page issues we'd have to >>> reduce the page size to a sector size, but I'm not sure that's that bad?
>> Giving up a dozen or two bytes out of every 512 sounds like quite an >> overhead. > It's not nothing, that's true. But if it avoids 8 bytes in every record, > that'd probably at least as much in most usecases. Fair point. I don't have a very good handle on what "typical" WAL record sizes are, but we might be fine with that --- some quick counting on the fingers says we'd break even with an average record size of ~160 bytes, and be ahead below that. We'd need to investigate the page-crossing overhead carefully though. regards, tom lane