On Mon, Apr 19, 2010 at 11:04 AM, Robert Haas <robertmhaas@gmail.com> wrote:
>> First of all, I wonder why the latter two need to affect the decision of
>> whether additional information is written to WAL for HS. How about just
>> removing XLogIsNeeded() condition from XLogStandbyInfoActive()?
>
> Bad idea, I think. If XLogIsNeeded() is returning false and
> XLogStandbyInfoActive() is returning true, the resulting WAL will
> still be unusable for HS, at least AIUI.
Probably No. Such a WAL will be usable for HS unless an unlogged
operation (e.g., CLUSTER, CREATE TABLE AS SELECT, etc) happens.
I think that the occurrence of an unlogged operation rather than
XLogIsNeeded() itself must be checked in the standby, it's already
been being checked. So just removing XLogIsNeeded() condition makes
sense to me.
Regards,
--
Fujii Masao
NIPPON TELEGRAPH AND TELEPHONE CORPORATION
NTT Open Source Software Center