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General DB2 Informix Oracle
   Recommendations  |   Performance papers

Initialization parameters used for Oracle I/O option measurements
Miscellaneous settings
Selecting the test scenario
I/O options
Relink Oracle for async I/O

Selecting the test scenario

The following settings are defined accordingly to the scenario, in addition to the parameters above:

Scenario

Description

plain fs

ext2 file system with:
DBWR_IO_SLAVES=20
DISK_ASYNCH_IO=FALSE

direct_io

ext2 file system with direct I/O:
DBWR_IO_SLAVES=20
DISK_ASYNCH_IO=FALSE
FILESYSTEMIO_OPTIONS
=DIRECTIO

async

ext2 file system with async I/O:
DB_WRITER_PROCESSES=1
DISK_ASYNCH_IO=TRUE
FILESYSTEMIO_OPTIONS=ASYNCH

Note: for this option a relink of the oracle database is required

setall

ext2 file system with direct I/O and async I/O:
DB_WRITER_PROCESSES=1
DISK_ASYNCH_IO=TRUE
FILESYSTEMIO_OPTIONS=SETALL

Note: for this option a relink of the oracle database is required

setall ext3

ext3 file system with direct I/O and async I/O:
DB_WRITER_PROCESSES=1
DISK_ASYNCH_IO=TRUE
FILESYSTEMIO_OPTIONS=SETALL

Note: for this option a relink of the oracle database is required

raw

raw devices with no further I/O options:
DBWR_IO_SLAVES=20
DISK_ASYNCH_IO
=FALSE
DB_WRITER_PROCESSES=1

raw-async

raw devices with async I/O:
DISK_ASYNCH_IO=TRUE
DB_WRITER_PROCESSES=1

Note: The option DBWR_IO_SLAVES must not be specified when async I/O is used!


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