On Fri, 2003-10-17 at 10:25, Shridhar Daithankar wrote:
OK. So here is what I understand. I have a table which contains 100 rows which appeated there due to some insert operation. Then I vacuum it. And sit there for internity for rest of the database to approach the singularity(the xid wraparound..:-) Nice term, isn't it?).
So this static table is vulnerable to xid wraparound? I doubt.
No that table would probably be ok, because you did a vacuum on it after
the inserts. The problem is that pg_autovacuum may choose not to do a
vacuum if you didn't cross a threshold, or someone outside of
pg_autovacuum may have done the vacuum and autovac doesn't know about
it, so it can't guarantee that all tables in the database are safe from
xid wraparound.
One additional thing, some of this might be possible if pg_autovacuum
saved its data between restarts. Right now it restarts with no memory
of what happened before.
Well, the unmaintened gborg version adopted approach of storing such info. in a table, so that it survives postgresql/pg_atuvacuum restart or both.
That was considered a tablespace pollution back then. But personally I think, it should be ok. If ever it goes to catalogues, I would rather add few columns to pg_class for such a stat. But again, thats not my call to make.
Shridhar
---------------------------(end of broadcast)--------------------------- TIP 5: Have you checked our extensive FAQ?
http://www.postgresql.org/docs/faqs/FAQ.html
