On Mon, Feb 19, 2007 at 05:10:36PM +0100, Dimitri Fontaine wrote: > > RAID and LVM too. I can't get excited about re-inventing those wheels > > when perfectly good implementations already exist for us to sit on top of. > > I though moving some knowledge about data availability into PostgreSQL code > could provide some valuable performance benefit, allowing to organize reads > (for example parallel tables scan/indexes scan to different volumes) and > obtaining data from 'quicker' known volume (or least used/charged).
Well, organising requests to be handled quickly is a function of LVM/RAID, so we don't go there. However, speeding up scans by having multiple requests is an interesting approach, as would perhaps a different random_page_cost for different tablespaces. My point is, don't try to implement the mechanics of LVM/RAID into postgres, instead, work on providing ways for users to take advantage of these mechanisms if they have them. Look at it as if you have got LVM/RAID setup for your ideas, how do you get postgres to take advantage of them? Have a nice day, -- Martijn van Oosterhout <email@example.com> http://svana.org/kleptog/ > From each according to his ability. To each according to his ability to > litigate.
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