Re: Flash technology based HDD will it make significant difference for OLTP applications?

From: Nigel Thomas <nigel_cl_thomas_at_yahoo.com>
Date: Mon, 7 Jan 2008 08:51:07 -0800 (PST)
Message-ID: <66024.31983.qm@web58813.mail.re1.yahoo.com>


See thread http://www.freelists.org/archives/oracle-l/09-2005/msg01024.html including pertinent comments from Cary Milsap, Kevin Closson, Nuno Souto and many more ...

And this more recent post from Kevin's Manly Men series: http://kevinclosson.wordpress.com/2007/07/21/manly-men-only-use-solid-state-disk-for-redo-logging-lgwr-io-is-simple-but-not-lgwr-processing/

An obvious disadvantage of a solid state disc is that it pretends to be a disc (ie it's an inefficient way of accessing what is effectively memory). You have to go through the I/O driver (and the cable - SCSI or what you will) before you actually get the data back. These mechanisms have been designed in the confident expectation that the turnaround time will be multiple milliseconds. Rather like going to the corner shop for a tin of beans rather than looking in the kitchen cupboard, methinks...

Regards Nigel

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Received on Mon Jan 07 2008 - 10:51:07 CST

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