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Rick Greenwald, Robert Stackowiak, Jonathan Stern

"Oracle Essentials: Oracle Database 11g"

Segregating the objects allows you
to directly monitor the I/O associated with each object. Your Oracle documentation
details the other factors to consider in mapping objects to tablespaces.
Place redo logs and redo log mirrors on the two least-busy devices
This placement maximizes throughput for transactional systems. Oracle writes
to all copies of the redo log file, and this I/O is not completed until all copies
have been successfully written to. If you have two copies of the redo log file, one
on a slow device and the other on a fast device, your redo log I/O performance
will be constrained by the slower device.
162 | Chapter 7: Oracle Performance
As described in Chapter 8, Oracle Database 10g Release 2 gives youthe option
of delaying write operations to the redo log for transactions. This capability can
improve performance in very high transactional environments, but carries with it
the possibility of losing committed data if your database crashes.
Distribute ???system overhead??? evenly over the available drives
System overhead consists of I/O to the SYSTEM tablespace for the data dictionary,
the TEMP tablespace for sorting, and the tablespaces that contain rollback
segments for undo information.


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