Oracle FAQ Your Portal to the Oracle Knowledge Grid
HOME | ASK QUESTION | ADD INFO | SEARCH | E-MAIL US
 

Home -> Community -> Mailing Lists -> Oracle-L -> KEEP pool and manually uncaching objects

KEEP pool and manually uncaching objects

From: <mteehan_at_erggroup.com>
Date: Tue, 13 Jun 2000 10:01:58 +0800
Message-Id: <10526.108820@fatcity.com>


I am waiting for a future release of oracle that will allow buffer pools to be defined for tables and indexes, each with its own buffer ageing rules. It fits in very well with partitioning by day for OLTP transactional databases, where only the current day needs to be cached. In the meantime, its a daily battle with the buffer flushing mechanisms. This is what I need to do :
I have an OLTP app where throughput is EVERYTHING - I mean peak rates of nearly 3000 transactions per second. Buffer ageing is critical- I cant afford to have required buffers flushed to disk.
Transactions are partitioned by business day, with a local index, and only the current day's index partition is in the KEEP pool. Not the transactions themselves : they are in recycle. This is to allow all index blocks to be cached to allow fast inserts to the index. At end of day, I will change the current index partition to the recycle pool, add a partition for the next day, and put its index in the KEEP pool. Here the fun starts - I would like to be able to flush all buffers for yesterdays' index to disk to make room for the todays index. For an index already in the KEEP pool, if I alter-table it to the recycle pool, will its buffers be aged out as new buffers are required, or are they marked 'KEEP' as part of the buffer header, and will never be aged out. In otherwords ; once a Keep buffer, always a Keep buffer? Has anyone tested this stuff?

Regards
Mark Teehan
Perth, Australia

Received on Mon Jun 12 2000 - 21:01:58 CDT

Original text of this message

HOME | ASK QUESTION | ADD INFO | SEARCH | E-MAIL US