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Subject: Re: Odd blocking (or massively latent) issue - even with
 EXPLAIN
From: Jim Vanns <james.vanns@framestore.com>
To: Martin French <Martin.French@romaxtech.com>
Cc: Jim Vanns <james.vanns@framestore.com>, pgsql-performance@postgresql.org,
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> > That latter test - won't that pretty much just read from the page
> cache?
> > 'sync' may well have forced dirty pages to disk but does it actually
> > evict them to?
> 
> Basically, the cache is avoided because of the size of the file.
> 6000000 blocks at 8k exceeds the size of RAM in the machine, so it
> *should* miss the cache and hit the disk directly. :)

Doh!

> > 
> > Anyway, that is off topic... perhaps ;)
> > 
> > Thanks again,
> > 
> > Jim
> > 
> 
> Cheers
> 
> Martin ============================================= Romax Technology
> Limited Rutherford House Nottingham Science & Technology Park
> Nottingham, NG7 2PZ England Telephone numbers: +44 (0)115 951 88 00
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-- 
Jim Vanns
Systems Programmer
Framestore