Re: Re: default opclass for jsonb (was Re: Call for GIST/GIN/SP-GIST opclass documentation)

On Wed, Apr 9, 2014 at 02:22:54PM -0400, Greg Stark wrote:
> On Wed, Apr 9, 2014 at 11:24 AM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
> >> Maybe we should make *neither* of these the default opclass, and give
> >> *neither* the name json_ops.
> >
> > There's definitely something to be said for that. Default opclasses are
> > sensible when there's basically only one behavior that's interesting for
> > most people. We can already see that that's not going to be the case
> > for jsonb indexes, at least not with the currently available alternatives.
> >
> > Not having a default would force users to make decisions explicitly.
> > Is that what we want?
>
> I don't like the idea of having no default opclass. I think there's a
> huge usability gain in being able to "just" create an index on a
> column and have it do something reasonable for most use cases.
>
> I can get behind the idea of having separate index opclasses for paths
> and path-value pairs but I suspect the default should just be to index
> both in the same index. If we can have one default index opclass that
> supports containment and existence and then other opclasses that are
> smaller but only support a subset of the operators that would seem
> like the best compromise.
>
> I'm a bit confused by Heikki's list though. I would expect path and
> path-value pair to be the only useful ones. I'm not clear what an
> index on keys or key-value would be -- it would index just the
> top-level keys and values without recursing?

Where are we on the default JSONB opclass change?

--
Bruce Momjian <bruce(at)momjian(dot)us> http://momjian.us
EnterpriseDB http://enterprisedb.com

+ Everyone has their own god. +