Re: Small GIN optimizations (after 9.4)

On Wed, Feb 12, 2014 at 2:58 AM, Bruce Momjian <bruce@momjian.us> wrote:

> On Sun, Feb  9, 2014 at 02:17:12PM +0400, Alexander Korotkov wrote:
> > On Thu, Feb 6, 2014 at 8:31 PM, PostgreSQL - Hans-J rgen Sch nig <
> > postgres@cybertec.at> wrote:
> >
> >     i think there is one more thing which would be really good in GIN
> and which
> >     would solve a ton of issues.
> >     atm GIN entries are sorted by item pointer.
> >     if we could sort them by a "column" it would fix a couple of real
> work
> >     issues such as ...
> >
> >             SELECT ... FROM foo WHERE "tsearch_query" ORDER BY price
> DESC LIMIT
> >     10
> >
> >     ... or so.
> >     it many cases you want to search for a, say, product and find the
> cheapest
> >     / most expensive one.
> >     if the tsearch_query yields a high number of rows (which it often
> does) the
> >     subsequent sort will kill you.
> >
> >
> > This is not intended to be a small change. However, some solution might
> be
> > possible in post 9.4 gin improvements or in new secret indexing project
> which
> > will be presented at PGCon :-)
>
> Would any of the listed changes cause backward-incompatible changes to
> the on-disk format, causing problems for pg_upgrade?
>

None of them.

------
With best regards,
Alexander Korotkov.