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RE: Block size or replication?

From: Singla, Sanjeev <>
Date: Tue, 20 Jun 2000 10:28:00 -0400
Message-Id: <>

If u increase the block size and u are using Oracle parallel server then there can be
potential issues of pinging the blocks accross nodes. Because with one block read into the
SGA there will be more records locked by the instance. There can be potential concurrency
and performance issues. But if u are single instance Oracle and u are running mixed jobs
(OLTP+Batch( then u can be better off with increasing the block size))
Another solution is to maitain a standby database (provided u r in Oracle 8.x) which will automatically
get refershed with the archive logs and whenever u want u can open it for batch (read only jobs).
But keep in mind to create ur temporary tablespace as locally managed. Because dictionary will be
in read only mode and ur reporting may need some temp sorts.


-----Original Message-----
From: Smith, Ron L. [] Sent: Tuesday, June 20, 2000 11:07 AM
To: Multiple recipients of list ORACLE-L Subject: Block size or replication?

We have an OLTP system that has frequent long running Crystal Reports reports that affect the overall online performance. We are looking at ways to improve response time. This is a purchased app and we do not modify code. We are looking at doing replication to offload some of the processing. But I am wondering if increasing the blocksize would be a better solution. The ad-hoc reports often do full table scans, as do the OLTP programs. This is even though there are indexes available. Remember we don't change code. The current block size is 4096. I would like to change it to 8192. I am thinking this would cut full table scan i/o in half and speed up processing. Any ideas?

Ron Smith
Database Administration

Author: Smith, Ron L.

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Received on Tue Jun 20 2000 - 09:28:00 CDT

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