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Re: Using SKYLINE command on PostgreSQL

From: Yeb Havinga <yebhavinga(at)gmail(dot)com>
To: Craig Ringer <craig(at)postnewspapers(dot)com(dot)au>
Cc: LaboRecherche <nomail(at)altranx(dot)com>, pgsql-sql(at)postgresql(dot)org
Subject: Re: Using SKYLINE command on PostgreSQL
Date: 2010-08-08 13:40:07
Message-ID: AANLkTinnVM-gqAXzV4jgr6F+CVH3wUa9R7inXmWHpDeP@mail.gmail.com (view raw or flat)
Thread:
Lists: pgsql-sql
On Sun, Aug 8, 2010 at 5:35 AM, Craig Ringer <craig(at)postnewspapers(dot)com(dot)au>wrote:

>
> The masters thesis page does contain a patch against PostgreSQL 8.3:
>  http://skyline.dbai.tuwien.ac.at/
>

That page has a nice web page and examples where queries can be run. 'The
skyline operator' is described in
http://www.dbis.ethz.ch/research/publications/38.pdf. It reminds me a bit of
the staircase join operator, something on my personal wish list for postgres
as well (latest patch seems to have got lost on the internet).

>
> They say they're porting the patch to 8.4devel, but I suspect that since
> 8.4 has been out for ages and 9.0 is almost released, they've probably
> lost interest and dropped the work.
>

I looked a bit in the latest patch. There's a lot of FIXME's and TODO's in
it. It adds at least one plan node, so it's probably hard to rewrite into
contrib form. That'll probably make it harder to get accepted for mainline
postgres, also because the skyline queries can be translated into 'normal'
sql (referenced pdf, section 3.1), though the authors claim the performance
using skyline is better. Since 8.3 CTE's have been introduced and maybe that
makes writing these kinds of queries easier. Also the knngist ordering of
'interesting points' might be a solution for problems in the same ballpark.

regards,
Yeb Havinga

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