Overview I/O Calibration
Oracle Database 11g introduces an I/O Calibration mechanism, whereby you can run I/O calibration tests either through the Enterprise Manager Performance page or a PL/SQL package. Oracle’s I/O calibration is a variation on the Clarion tool. In an Oracle database, the I/O workload is of two basic types—small random I/O and large sequential I/O. OLTP applications usually experience the small random I/O workload, where the speed with which small I/O requests are serviced is paramount. Thus, disk spinning and seeking times are of critical importance. OLAP applications, on the other hand, employ the large sequential I/O in general. For these types of applications, the critical factor is the capacity of the I/O channel. The larger the I/O channels between the database server and the storage system, the larger the I/O throughput. Oracle uses the following two metrics, each measuring the efficacy of one type of I/O workload:Oracle Database 11g intro
