On Mon, Nov 13, 2023 at 10:51 PM Robert Haas <robertmh...@gmail.com> wrote: > > On Mon, Nov 13, 2023 at 12:47 AM Hayato Kuroda (Fujitsu) > <kuroda.hay...@fujitsu.com> wrote: > > Moved. > > I see that this patch was committed, but I'm not very convinced that > the approach is correct. The comment says this: > > + /* > + * A write buffer needs to be registered even if no tuples are > + * added to it to ensure that we can acquire a cleanup lock on it > + * if it is the same as primary bucket buffer or update the > + * nextblkno if it is same as the previous bucket buffer. > + */ > > But surely if the buffer is the same as one of those others, then it's > registered anyway,
I don't think for others it's registered. For example, consider the case when prevpage and the writepage are the same (aka xlrec.is_prev_bucket_same_wrt is true), it won't be registered in another code path (see comment [1]). > > and if it isn't, then it doesn't need to be. > In the previous example, we need it to update the nextblockno during replay. I am not sure if I understand the scenario you are worried about, so if my response doesn't address your concern, can you please explain a bit more about the scenario you have in mind? [1] - /* * If prevpage and the writepage (block in which we are moving tuples * from overflow) are same, then no need to separately register * prevpage. During replay, we can directly update the nextblock in * writepage. */ -- With Regards, Amit Kapila.
