Horton

Re: I: About "Our CLUSTER implementation is pessimal" patch

Tom Lane <tgl@sss.pgh.pa.us>

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From: Tom Lane <tgl@sss.pgh.pa.us>
To: Simon Riggs <simon@2ndQuadrant.com>
Cc: Alvaro Herrera <alvherre@commandprompt.com>, Itagaki Takahiro <itagaki.takahiro@gmail.com>, Josh Kupershmidt <schmiddy@gmail.com>, Leonardo Francalanci <m_lists@yahoo.it>, pgsql-hackers <pgsql-hackers@postgresql.org>
Date: 2010-09-30T19:04:29Z
Lists: pgsql-hackers 
Simon Riggs <simon@2ndQuadrant.com> writes:
> On Wed, 2010-09-29 at 08:44 -0400, Alvaro Herrera wrote:
> So, I think "twice disk space of the sum of table and indexes" would be
> the simplest explanation for safe margin.
>> 
>> Agreed.

> Surely the peak space is x3?
> Old space + sort space + new space.

The wording should be something like "CLUSTER requires transient disk
space equal to about twice the size of the table plus its indexes".

			regards, tom lane