----- Original Message -----
From: "Tom Lane" <tgl(at)sss(dot)pgh(dot)pa(dot)us>
> How much later? clog is not kept forever.
Due to my setup, I could assure, that for the XID I ask for always
(ShmemVariableCache->nextXid - XID) < C (and C is in my case something
around 150).
holds. A possible solution could be to (dynamically) announce this constant
C to the clog code,
so that the information is kept for a while. Ofcourse one should not do a
VACUUM FULL while not being sure about the status of a transaction in the
past :)
Until now, I did not investigate what happens when
ShmemVariableCache->nextXid wraps around.
- Christian