Re: 10 weeks to feature freeze (Pending Work)

"Rick Gigger" <rick(at)alpinenetworking(dot)com> writes:

> I thought that the following todo item just barely missed 8.2:
>
> "Allow a warm standby system to also allow read-only statements [pitr]
> This is useful for checking PITR recovery."

No, nobody worked on it prior to 8.2. Afaik there's still nobody working on
it. It's not trivial. Consider for example that your read-only query would
still need to come up with a snapshot and there's nowhere currently to find
out what transactions were in-progress at that point in the log replay.

There's also the problem that currently WAL replay doesn't take have allow for
any locking so there's no way for read-only queries to protect themselves
against the WAL replay thrashing the buffer pages they're looking at.

It does seem to be doable and I agree it would be a great feature, but as far
as I know nobody's working on it for 8.3.

--
Gregory Stark
EnterpriseDB http://www.enterprisedb.com