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Home -> Community -> Mailing Lists -> Oracle-L -> RE: db_file_multiblock_read_count and performance
> On my linux box at work the 'ideal' would be 128. Keep in mind
> that the value of DBFMBRC will influence the CBO. You may
> find it favoring FTS more often than you would like.
I would think ideal is "as fast as possible" and assuming you tell Oracle the truth about speed of multiblock reads verse single block with optimizer_index_cost_adj everything should work out fine, even if full scans are favored. Of course too many scans at the same time and optimizer_index_cost_adj is no longer valid because IO bandwidth may effect response times, so I guess this is where system stats has a supreme advantage.=20
-- http://www.freelists.org/webpage/oracle-lReceived on Tue Dec 07 2004 - 13:24:39 CST
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