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Memory based tables

From: Ondrej Florian <OFlorian.geo_at_yahoo.com>
Date: Tue, 19 Jul 2005 06:32:58 +0200
Message-Id: <30C0EEA4-1108-40FF-9523-03F19757EE07@yahoo.com>


Hello,
I would like to know if there is such a thing as memory based table in Oracle. What I mean be memory based is table which doesn't require any disk IO for storing or retrieving data. I am working on a project that includes price database which is obviously very IO intensive by nature. Since I can afford to loose some data during the server crash, I though about putting them all into memory. The reason why I cannot use something like MySQL or even some home grown kind of solution is that prices are to be combined with our static data and it is essential to keep everything in one database. One part of the solution is to cache data in the database for read access and this works very well. The problem is the write access. Since price updates are spread over long time period, it is very hard to do any type of mass import. So essentially you end up with a lot of small insert, update, delete transactions which means the the the performance suffers. Now I tried to do something every stupid. I moved the redo logs into a ramdisk. Something that the real DB would never do. Hey, I am not a DBA, I am programmer :-). Anyhow I got about 10x faster throughput without sweat. Obviously the problem is what happens when there is a crash. Loosing the data it self is not big deal. The problem is that as I found out Oracle has really hard time dealing with deleted redo logs. In the end I had to reinstall the whole database. Not really surprising outcome, but it got me thinking. Is there a safe way to eliminate disk IO in Oracle ?

I hope my question is understandable enough, Thanks for your response,

Ondrej

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Received on Mon Jul 18 2005 - 23:34:36 CDT

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