Re: 500 tpsQL + WAL log implementation

From: "Peter Galbavy" <peter(dot)galbavy(at)knowtion(dot)net>
To: "Bruce Momjian" <pgman(at)candle(dot)pha(dot)pa(dot)us>, "Curtis Faith" <curtis(at)galtcapital(dot)com>
Cc: <pgsql-hackers(at)postgresql(dot)org>
Subject: Re: 500 tpsQL + WAL log implementation
Date: 2003-05-24 10:54:37
Message-ID: 014101c321e2$dec5b410$24e0a8c0@HATMADDER
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Bruce Momjian wrote:
> the idea is to have multiple versions of the last WAL block, meaning
> you
> write the first record of the last block, then when you want to write
> another, your disk platter has moved, so you write the first and
> second records in a new location.

But how much of this is entirely dependent on deterministic prediction of
the disk activity ?

Not only noting the way modern disks have their own write caches (most IDE
drives now come with between 2 and 8 MB), but transparent bad sector
remapping and also filesystem issues with ufs, ext2 and journalling
extensions to both.

While I believe that there is value is working towards a better coupling
between PosetgreSQL and the underlying hardware, is this approach going to
be productive in the "real" world ? Enough to spend time on it ?

Your choice mind, I am just whining.

Peter

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