Re: 10 weeks to feature freeze (Pending Work)

Rick Gigger <rick@alpinenetworking.com>

From: Rick Gigger <rick@alpinenetworking.com>
To: Gregory Stark <stark@enterprisedb.com>
Cc: "Joshua D. Drake" <jd@commandprompt.com>, PostgreSQL-development <pgsql-hackers@postgresql.org>
Date: 2007-02-07T00:04:52Z
Lists: pgsql-hackers
Gregory Stark wrote:
> "Rick Gigger" <rick@alpinenetworking.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.

Thanks again for the update.