On Monday, September 17, 2012 12:35:32 AM Tom Lane wrote: > Andres Freund <and...@2ndquadrant.com> writes: > > This requires the previously added RELFILENODE syscache. > > [ raised eyebrow... ] There's a RELFILENODE syscache? I don't see one, > and I doubt it would work given that the contents of > pg_class.relfilenode aren't unique (the zero entries are the problem). Well, one patch upthread ;). It mentions the problem of it not being unique due to relfilenode in (reltablespace, relfilenode) being 0 for shared/nailed catalogs.
I am not really sure yet how big a problem for the caching infrastructure it is that values that shouldn't ever get queried (because the relfilenode is actually different) are duplicated. Reading code about all that atm. Robert suggested writing a specialized cache akin to whats done in attoptcache.c or such. I haven't formed an opinion on whats the way forward on that topic. But anyway, I don't see how the wal decoding stuff can progress without some variant of that mapping, so I sure hope I/we can build something. Changing that aspect of the patch should be trivial... Greetings, Andres -- Andres Freund http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Training & Services -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
