On Wed, Dec 17, 2025 at 9:49 AM Michael Paquier <[email protected]> wrote: > > On Sat, Dec 13, 2025 at 01:34:47PM -0600, Naga Appani wrote: > > Documentation changes: > > - Removed the NULL-return discussion from func-info.sgml, as the > > statistics are now always available. > > - Updated maintenance.sgml to clarify that exceeding the historical > > 2^32 member limit no longer causes wraparound, but instead triggers > > more aggressive vacuum activity for disk space management. > > > > I validated the behavior before and after cleanup. > > The function correctly reports current usage (beyond the old limits) and > > resets once multixacts are removed: > > + /* > + * Calculate storage space for members. Members are stored in groups, > + * with each group containing MULTIXACT_MEMBERS_PER_MEMBERGROUP > members > + * and taking MULTIXACT_MEMBERGROUP_SIZE bytes. > + */ > + membersBytes = (int64) (members / MULTIXACT_MEMBERS_PER_MEMBERGROUP) * > + MULTIXACT_MEMBERGROUP_SIZE; > > This is the key point of the patch internal logic. And there is one > thing that I am wondering here. The amount of space taken by a number > of members depends on the other compiled constants from > multixact_internal.h. Hence, rather than calculate the amount of > space taken by a set of members in some code hidden in the SQL > function, could it be better to put that directly as a macro or an > inline function in multixact_internal.h?
+1. -- Best Wishes, Ashutosh Bapat
