Veritas ODM and Oracle 9i

Oracle 9.2.0.4 (64-bit)
Veritas version 1
Solaris 9

We have performed various tests on Oracle db_file_scattered_read performance in various combinations of:

VxFS - with and without ODM
VxVM partition - with and without ODM
VTOC partition - with and without ODM

and tried various combinations of db_block_size.

Whilst we can get VxFS and any raw partition to perform IOs in db_file_multiblock_read_count * db_block_size requests, any use of ODM always results in the transfers being of db_block_size. This is clearly less effcient since more requests must be issued for this kind of read.

This seems at odds with the documentation which claims that odm_io() will perform sequential reads/writes, direct read/writes, scattered reads, dbwr batch writes etc in the most efficient manner available.

Is there any way that the behaviour of ODM can be influenced such that scattered reads are performed in db_file_multiblock_read_count * db_block_size requests?

Cheers

Ralph Received on Tue Nov 30 2004 - 09:47:16 CST