Re: Converting MySQL tinyint to PostgreSQL

From: Ron Mayer <rm_pg(at)cheapcomplexdevices(dot)com>
To: Martijn van Oosterhout <kleptog(at)svana(dot)org>
Subject: Re: Converting MySQL tinyint to PostgreSQL
Date: 2005-07-13 13:50:23
Message-ID: 42D51C1F.8070506@cheapcomplexdevices.com
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Martijn van Oosterhout wrote:
>
> Well, you get another issue, alignment. If you squeeze your string
> down, the next field, if it is an int or string, will get padded to a
> multiple of 4 negating most of the gains. Like in C structures, there
> is padding to optimise access.

Anecdotally I hear at least as many people say that their database
is more I/O bound than CPU bound; and it seems that adding bytes
for alignment is a way of reducing CPU for more disk I/O.

I guess unaligned access so expensive that it makes up for the extra i/o?

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