Re: machine-readable pg_controldata?

Heikki Linnakangas wrote:
> Then again, if you don't use the copy in shared memory but just open the
> pg_control file and read it in the UDF, you could implement this as a
> pgfoundry module that works with older versions too.
>

This is the direction I'd prefer to see this go in a 9.0 context. It's
easy enough to build a fully functional version that lives works via the
same proposed final UDF interface, just with the extra step of reading
the file. Get that working, and you just added a useful module
supporting all the way back to 8.2 (I think--not sure if there's been
any other changes that would break this) that people would love to have.

Once it's done, the UI is solid, all the data is known to be exposed in
the right way it turns out people wanted it to be, then do the simple
conversion it to grab from shared memory instead and add it as an
official 9.1 feature. I'm not feeling any pressure that this is a
must-fix item for the 9.0 release freeze--as warts here go, this is a
both a small one and one that doesn't have to be fixed in core, so two
strikes against it being critical.

I would rather have the ability to tweak on this for a few months to get
everything right, while being able to expose regular updates outside of
core, than to commit "this is the best we've got so far" just under the
wire for 9.0 without necessarily enough time to do it well. The few
messages that have shown up here already have made left me with the
optinion that just getting the requirements and preferred implementation
nailed down here is going to take a few rounds of development to work
out to everyone's satisfaction.

--
Greg Smith 2ndQuadrant US Baltimore, MD
PostgreSQL Training, Services and Support
greg(at)2ndQuadrant(dot)com www.2ndQuadrant.us