Re: No longer possible to query catalogs for index capabilities?

On Mon, Aug 1, 2016 at 10:19 AM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:

> Stephen Frost <sfrost(at)snowman(dot)net> writes:
> > * Tom Lane (tgl(at)sss(dot)pgh(dot)pa(dot)us) wrote:
> >> Building on the has-property approach Andrew suggested, I wonder if
> >> we need something like pg_index_column_has_property(indexoid, colno,
> >> propertyname) with properties like "sortable", "desc", "nulls first".
>
> > Right, this makes sense to me. The point which I was trying to get at
> > above is that we should be able to replace most of what is provided in
> > pg_get_indexdef() by using this function to rebuild the CREATE INDEX
> > command- again, similar to how we build a CREATE TABLE command rather
> > than simply provide a 'pg_get_tabledef()'.
>
> As far as I understood Andrew's use case, he was specifically *not*
> interested in a complete representation of an index definition, but
> rather about whether it had certain properties that would be of
> interest to query-constructing applications.
>
>
+1

I guess it might matter whether the query be constructed is CREATE INDEX or
SELECT

The later seems to be more useful. The former should probably be something
the server provides as a whole when requested.

David J.
​