Summary

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As you have seen in this chapter, the I/O subsystem is an extremely important component of your database system. You have learned how a disk drive works and what its limitations are. By knowing the limits of the disk drive, you can configure your system to work within those limits. By knowing the characteristics of the RAID levels, you can now configure your system to take advantage of those characteristics. When designing your system, you must carefully size and tune the I/O subsystem. I/O tuning is all about capacity. By working within the capacity of the various components, you can achieve optimal system performance.