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Home -> Community -> Mailing Lists -> Oracle-L -> RE: recycle and keep buffer in other tablespace block sizes
Since Oracle has emphatically and repeatedly stated they do not intend
varying block sizes as a performance tool, I believe they intentionally did
not create keep and recycle pools for alternate sizes in a database. And
they are moving toward overall target sizes rather than user specified
allocations.
Although I have some theories I'm researching regarding using alternate block sizes for performance purposes in 10g, I'll refrain from reporting results until I have a PDB (pretty damned bulletproof) example set. If the results prove simple enough to manage and of substantial benefit, adding those allocations might seem reasonable (although it pretty much flies in the face of the trend toward using a target size and having the actual usage of the instance drive dynamic self tuning.)
I haven't seen a thread on experimental results of the effects of using multiple block sizes on throughput. If anyone has such results to share, I wouldn't mind skipping the reinvention of the wheel. (Please note I'm not asking for new speculations on likely to work cool tricks to benefit performance with multiple block sizes -- I've already got a longer list than I really want to test.) Also, I'm more interested in thoughtful attempts to establish that benefit can be gained (whether successful or not) than in the infinite number of cases that can easily be concocted to show no difference.
(The stated intent of supporting multiple block sizes is to support transportable tablespaces amongst databases with varying block sizes.)
mwf
-----Original Message-----
From: oracle-l-bounce_at_freelists.org
[mailto:oracle-l-bounce_at_freelists.org]On Behalf Of Juan Carlos Reyes
Pacheco
Sent: Wednesday, July 21, 2004 9:58 AM
To: oracle-l_at_freelists.org
Subject: recycle and keep buffer in other tablespace block sizes
Hi list I'm investigating this,
if your default blocksize is 8k, and you create a tables using 2k block
you have the
ALTER SYSTEM SET DB_2K_CACHE_SIZE = 100M;
to set the size for this block cache
But how do you set the keep and recycle size for this block size
There are none of this parameter.
ALTER SYSTEM SET DB_2K_KEEP_CACHE_SIZE = 1M;
ALTER SYSTEM SET DB_2K_RECYCLE_CACHE_SIZE = 1M;
Thank you
Juan Carlos Reyes Pacheco
OCP
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