Re: CLUSTER command

From: Jean-Luc Lachance <jllachan(at)nsd(dot)ca>
To: Stephan Szabo <sszabo(at)megazone23(dot)bigpanda(dot)com>
Cc: pgsql-general(at)postgresql(dot)org, pgsql-performance(at)postgresql(dot)org
Subject: Re: CLUSTER command
Date: 2002-12-12 22:15:37
Message-ID: 3DF90A89.61040846@nsd.ca
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-general pgsql-interfaces pgsql-performance

The current cluster command is equivalant to:

create b as select * from a order by i;

So you would not be loosing anything.

Stephan Szabo wrote:
>
> On Thu, 12 Dec 2002, Jean-Luc Lachance wrote:
>
> > Hi all,
> >
> > I just read about the cluster command and was a little (very)
> > disapointed.
> > Clustered tables do not remain clustered after inserts.
> > Clustered tables are usefull when the table is very large and there are
> > few different keys.
> >
> >
> > Because the table file is already extended (2G limit) using different
> > files extension (.N)
> > how complicated (modifying the code) would it be to have the table files
> > split according to the cluster key?
>
> I'd vote against changing the existing CLUSTER since the existing CLUSTER
> while not great does handle many different key values fairly well as well
> and this solution wouldn't. Many different key values are still
> useful to cluster if you're doing searches over ranges since it lowers the
> number of heap file reads necessary. If done this should probably be
> separate from the existing cluster or at least both versions should be
> possible.

In response to

Responses

Browse pgsql-general by date

  From Date Subject
Next Message johnnnnnn 2002-12-12 22:26:41 Re: [GENERAL] CLUSTER command
Previous Message Jean-Luc Lachance 2002-12-12 22:07:46 Re: Frustration with date/times/epoch in v7.3.

Browse pgsql-interfaces by date

  From Date Subject
Next Message johnnnnnn 2002-12-12 22:26:41 Re: [GENERAL] CLUSTER command
Previous Message Stephan Szabo 2002-12-12 22:03:56 Re: CLUSTER command

Browse pgsql-performance by date

  From Date Subject
Next Message johnnnnnn 2002-12-12 22:26:41 Re: [GENERAL] CLUSTER command
Previous Message Stephan Szabo 2002-12-12 22:03:56 Re: CLUSTER command