Re: Online verification of checksums

On Wed, Mar 06, 2019 at 08:53:57PM +0100, Tomas Vondra wrote:
> Not sure. AFAICS that would to require a single transaction, and if we
> happen to add some sort of throttling (which is a feature request I'd
> expect pretty soon to make it usable on live clusters) that might be
> quite long-running. So, not great.
>
> If we want to run it from the server itself, then I guess a background
> worker would be a better solution. Incidentally, that's something I've
> been toying with some time ago, see [1].

It does not prevent having a SQL function which acts as a wrapper on
top of the whole routine logic, does it?  I think that it would be
nice to have the possibility to target a specific relation and a
specific page, as well as being able to check fully a relation at
once.  It gets easier to check for page ranges this way, and the
throttling can be part of the function doing a full-relation check.
--
Michael