On 2016-09-04 21:09:41 -0400, Tom Lane wrote:
> Andres Freund <andres@anarazel.de> writes:
> > On 2016-09-04 11:55:06 -0400, Tom Lane wrote:
> >> It is becoming clear that the current extension update mechanism is kind
> >> of brute-force for this sort of change. I have no ideas offhand about a
> >> better way to do it, but like Peter, I was dismayed by the amount of pure
> >> overhead involved in the PARALLEL SAFE updates.
>
> > Agreed. I think one way, which a few extensions are taking, is to have a
> > base version and then incremental version upgrades. Currently CREATE
> > EXTENSION doesn't natively support that, so you have to concatenate the
> > upgrade scripts. I think it'd be great if we could add a 'baseversion'
> > property to the extension control file. When you create a new extension,
> > it'll start with the base version and then use the existing code to find
> > a path to upgrade to the target version. That also makes it a lot
> > easier to actually properly test extension upgrade paths, something
> > we've not really been good at.
>
> Hm, couldn't we do that automatically? At least in the case where only
> one base-version script is available?
You mean determining the baseversion? Hm, yes, that might work. But I'm
not sure how much we can rely on no earlier scripts being already
installed or such. Seems like a problem you'd possibly only encounter in
the field or dirty development environments.
Andres