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From: Josh Berkus <[email protected]>
To: [email protected]
Subject: Re: VLDB Features
Date: Wed, 12 Dec 2007 10:55:53 -0800
Message-ID: <[email protected]> (raw)
In-Reply-To: <[email protected]>
References: <[email protected]>
	<[email protected]>
	<[email protected]>

Markus,

> > Parallel Query
>
> Uh.. this only makes sense in a distributed database, no? I've thought
> about parallel querying on top of Postgres-R. Does it make sense
> implementing some form of parallel querying apart from the distribution
> or replication engine?

Sure.  Imagine you have a 5TB database on a machine with 8 cores and only one 
concurrent user.  You'd like to have 1 core doing I/O, and say 4-5 cores 
dividing the scan and join processing into 4-5 chunks.

I'd say implementing a separate I/O worker would be the first step towards 
this; if we could avoid doing I/O in the same process/thread where we're 
doing row parsing it would speed up large scans by 100%.  I know Oracle does 
this, and their large-table-I/O is 30-40% faster than ours despite having 
less efficient storage.

Maybe Greenplum or EnterpriseDB will contribute something.  ;-)

> > Windowing Functions
>
> Isn't Gavin Sherry working on this? Haven't read anything from him
> lately...

Me neither.  Swallowed by Greenplum and France.

-- 
Josh Berkus
PostgreSQL @ Sun
San Francisco

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