On Fri, Oct 20, 2023 at 8:55 PM Noah Misch <n...@leadboat.com> wrote: > > > I lean toward fixing this by > > > having amcheck scan left; if left links reach only half-dead or deleted > > > pages, > > > that's as good as the present child block being P_LEFTMOST. > > > > Also my preference. > > Done mostly that way, except I didn't accept deleted pages. Making this work > on !readonly would take more than that, and readonly shouldn't need that.
That makes sense to me. I believe that it's not possible to have a string of consecutive sibling pages that are all half-dead (regardless of the BlockNumber order of sibling pages, even). But I'd probably have written the fix in roughly the same way. Although...maybe you should try to detect a string of half-dead pages? Hard to say if it's worth the trouble. Suggest adding a CHECK_FOR_INTERRUPTS() call to the loop, too, just for good luck. > After I fixed the original error, the "block %u is not leftmost" surfaced > next. The attached patch fixes that, too. I didn't investigate the others. > The original test was flaky in response to WAL flush timing, but this one > survives thousands of runs. Hmm. Can't argue with that. Your fix seems sound. -- Peter Geoghegan
