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Re: [PATCHES] pg_freespacemap question

Mark Kirkwood <markir@paradise.net.nz>

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From: Mark Kirkwood <markir@paradise.net.nz>
To: Tatsuo Ishii <ishii@sraoss.co.jp>
Cc: tgl@sss.pgh.pa.us, alvherre@commandprompt.com, peter_e@gmx.net, pgsql-hackers@postgresql.org, pgsql-patches@postgresql.org
Date: 2006-03-12T22:48:33Z
Lists: pgsql-hackers 
Tatsuo Ishii wrote:
> BTW, I noticed difference of outputs from pg_freespacemap and
> pgstattuple.
> 
> I ran pgbench and inspected "accounts" table by using these tools.
> 
> pg_freespacemap:
> 	sum of bytes: 250712
> 
> pgstattuple:
> 	free_space: 354880
> 
> Shouldn't they be identical?

I would have thought so - unless there are not enough pages left in the 
FSM...

pg_freespacemap is reporting on what gets into the FSM - so provided I 
haven't put a bug in there somewhere (!) - we need to look at how VACUUM 
reports free space to the FSM....

cheers

Mark