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RE: excessive number of db writer

From: Laimutis Nedzinskas <Laimutis.Nedzinskas_at_landsbanki.is>
Date: Wed, 6 Sep 2006 17:19:55 -0000
Message-ID: <5A8896FB2AFC5445A7DCFC5903CCA6B06FEA9B@W03856.li01r1d.lais.net>


> From: oracle-l-bounce_at_freelists.org

[mailto:oracle-l-bounce_at_freelists.org] On Behalf Of Kevin
> As an aside, and as usual for the sake of history, the idea of
multiple writers (processes that build their own write batches) was not considered until the dawn of NUMA systems in the mid-to-late 90s. See, having a single writer build batches and task slaves is absolute murder on a NUMA system. All dbwr latching activity had to take place in the L3 of the building block where dbwr happened to be running. It was, um, horrible. So, Tirthanker Lahiri listened to our findings and analysis of our bus traces and implemented multiple true database writers...how nice. There is more info about that in James Morle's book...

Is it known what exactly is the difference between Oracle's dbwr "master-slaves" and "mutiple dbwr"? As far as I understand it is about making access to LRU *parallel* by adding multiply LRU lists, isn't it? Fyrirvari/Disclaimer
http://www.landsbanki.is/disclaimer

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Received on Wed Sep 06 2006 - 12:19:55 CDT

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