On 2017-03-22 10:14:14 -0400, Tom Lane wrote: > Andres Freund <and...@anarazel.de> writes: > > I propose that for each pg_class entry we start to keep the following > > additional metadata: > > - CATALOG_VERSION_NO at relation creation > > - PG_VERSION_NUM at relation creation > > - CATALOG_VERSION_NO at last full scan by vacuum > > - PG_VERSION_NUM at last full scan by vacuum > > (1) It's very very hard for me to believe that we need *two* versions of > the version number. Pick one.
PG_VERSION_NUM is probably enough, alright. > (2) How you gonna update this in vacuum? It cannot do a transactional > update. I think we can just do that in a separate transaction, at the tail end of vacuum_rel() - if we crash just before that, not that much is lost. That requires to hand up whether the whole table is scanned, which'd not be entirely pretty. Alternatively we could "just" PROC_IN_VACUUM* in lazy_vacuum_rel(), but that seems like a cure worse than the disease. Greetings, Andres Freund -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
