On Wed, May 27, 2026 at 10:18 PM Zhijie Hou (Fujitsu) <[email protected]> wrote: > > On Thursday, May 28, 2026 11:34 AM Amit Kapila <[email protected]> > wrote: > > On Wed, May 27, 2026 at 5:31 PM Amit Kapila <[email protected]> > > wrote: > > > > > > On Wed, May 27, 2026 at 1:08 AM Zhijie Hou (Fujitsu) > > > <[email protected]> wrote: > > > > > > > > 0001 remains unchanged. > > > > > > > > > > Few minor comments: > > > ================= > > > > Commit message says: "This change does not advance catalog_xmin. > > REPACK already holds a snapshot that prevents catalog dead tuple removal, > > so catalog_xmin handling can be addressed independently.". > > Isn't it equally important to advance this, otherwise, for long running > > REPACKs > > dead tuples will be accumulated needlessly? If so, do we have any ideas to > > avoid this? > > My understanding is that dead tuple accumulation is common to all long-running > commands (including CLUSTER, VACUUM FULL, and REPACK without CONCURRENTLY). As > long as a command holds a snapshot for a long time while scanning and copying > data, the backend xmin will cause similar accumulation. So, this doesn't seem > like a new issue to me, and given that catalog_xmin only affect tuples in > system > catalog which is less harmful, I thought it could be handled independently. > There was a proposal to improve this case in [1]. >
Fair enough. It makes sense to deal with catalog_xmin separately. > Attaching the v4 patch which improved the comments and commit message as > suggested. > I haven't tested it but otherwise the code changes looks good to me. -- With Regards, Amit Kapila.
