Oracle and Open Source

Improving Performance on Linux

Let’s assume that you’ve been able to install Oracle on Linux, but you’re not satisfied with its performance. In addition to all the usual tuning tricks you can try on any Oracle database, check out the following specific suggestions for Linux ports. These suggestions should really make your Oracle/Linux system fly:

Use raw I/O as of the Linux 2.4 kernel

As of the 2.4 release, Linux includes raw I/O support. Adopted from the commercial Unix world, the raw I/O feature enables data to be written directly to disk without being buffered by the filesystem. With the raw I/O device, you can create a datafile that does not exist in the filesystem; nevertheless, Oracle can easily and efficiently write to this datafile.

Use the ext3fs filesystem

Linux 2.4 includes a new filesystem that provides journaling and various speed optimizations. Journaling provides crash recovery protection by writing changes to a change log. In the event of a crash, cached changes can be used to restore data by rolling forward or backward. Of course, Oracle already provides this type of recovery via mirrored redo logs, control files, and datafiles, so most Oracle users will find the speed improvements available in the Linux 2.4 release to be the most useful new features.

Use RAIDed disks

Linux supports various RAID controllers that can be used to bundle disks together, interacting with them as a unit. RAID provides features such as these:

• Hot swapping, which allows a new drive to ...