Subject: Re: VLDB Features
From: Simon Riggs <simon@2ndquadrant.com>
To: josh@agliodbs.com
Cc: pgsql-hackers@postgresql.org, Hannu Krosing <hannu@skype.net>
In-Reply-To: <200712111531.25838.josh@agliodbs.com>
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	<200712111053.11178.josh@agliodbs.com>
	<1197407281.7138.4.camel@hannu-laptop>
	<200712111531.25838.josh@agliodbs.com>
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Date: Tue, 11 Dec 2007 23:57:23 +0000
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On Tue, 2007-12-11 at 15:31 -0800, Josh Berkus wrote:

> Here's the other VLDB features we're missing:
> 
> Parallel Query
> Windowing Functions
> Parallel Index Build (not sure how this works exactly, but it speeds Oracle 
> up considerably)
> On-disk Bitmap Index (anyone game to finish GP patch?)

I would call those VLDB Data Warehousing features to differentiate
between that and the use of VLDBs for other purposes.

I'd add Materialized View support in the planner, as well as saying its
more important than parallel query, IMHO. MVs are to DW what indexes are
to OLTP. It's the same as indexes vs. seqscan; you can speed up the seq
scan or you can avoid it. Brute force is cool, but being smarter is even
better. 

The reason they don't normally show up high on anybody's feature list is
that the TPC benchmarks specifically disallow them, which as I once
observed is very good support for them being a useful feature in
practice. (Oracle originally brought out MV support as a way of
improving their TPC scores at a time when Teradata was wiping the floor
with parallel query implementation). 

-- 
  Simon Riggs
  2ndQuadrant  http://www.2ndQuadrant.com