Tom Lane wrote: > Alvaro Herrera <[EMAIL PROTECTED]> writes: > > As far as I can see, for the purposes of VACUUM we can remove any tuple > > that was deleted after the old transaction's Xid but before that > > transaction's Xmin (i.e. all of its live snapshots). This means we get > > to ignore Xid in GetOldestXmin and in the TransactionXmin calculations > > in GetSnapshotData. It would not surprise me, however, to find out that > > I am overlooking something and this is incorrect. > > This seems entirely off-base to me. In particular, if a transaction > has an XID then its XMIN will never be greater than that, so I don't > even see how you figure the case will arise.
My point exactly -- can we let the Xmin go past its Xid? You imply we can't, but why? -- Alvaro Herrera http://www.CommandPrompt.com/ PostgreSQL Replication, Consulting, Custom Development, 24x7 support -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
