DB2 Performance Advice: SQL/Sec

Frankly, rates are not very helpful when it comes to tuning, but they are entertaining. You see, your business may be busier on Monday than it is on Wednesday. Or, your business may be busier at the end of a month versus the middle of a month. Rates can vary depending upon demand for services.

When evaluating database tuning efficiency and effectiveness, cost metrics provide a much better indicator of tuning success or failure. A number of cost metrics to help you assess the effectiveness and efficiency of your tuning efforts:

• Database Bufferpool Logical Reads per Transaction
• >Sorts per Transaction
• Hash Joins per 1,000 Transactions

Since some people like to monitor their databases to see how fast they are going, it provides "Statements Per Second" as a performance metric for informational purposes only. The value shown is the delta of statement count activity (SELECT_SQL_STMTS + UID_SQL_STMTS + DDL_SQL_STMTS) since the prior measurement was taken.

As an aside, SQL/Second may be helpful for capacity planning or validating the effectiveness of tuning. After several iterations of tuning activities, you may observe SQL activity throughput rates increase. However, again, any such increase could be due to normal changes in business activity.

Enjoy.

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