"Dawid Kuroczko" <qnex42@gmail.com> wrote:
> I am sure the idea is not original, yet still I would like to know how hard
> would it be to support local (per table) oldest visible XIDs.
>
> I mean, when transaction start you need to keep all tuples with xmin >=
> oldest_xid in all tables, because who knows what table will that transaction
> like to touch.
Per-table oldest XID management sounds good! You mean transactions
that touch no tables does not affect vacuums at all, right?
If so, the solution can resolve pg_start_backup problem, too.
I feel it is enough for standard maintenance commands.
Another solution might need for user defined long transactions, though.
Regards,
---
ITAGAKI Takahiro
NTT Open Source Software Center
