Re: Small GIN optimizations (after 9.4)

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(at)cybertec(dot)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?

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

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