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Beginning Oracle Database 11g Administration From Novice to Professional

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CHAPTER 17 SQL TUNING 411<br />

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But Wait, There’s More!<br />

Executing a query requires at least one consistent get operation. However, there is no<br />

need <strong>to</strong> execute the query if the query results have been previously cached and the data<br />

has not changed. <strong>Oracle</strong> <strong>11g</strong> introduced the hint <strong>to</strong> indicate that the data should<br />

be obtained from cache if possible. Note that this feature is available only with the Enterprise<br />

Edition. In the following example, you can see that the number of consistent gets<br />

has been reduced <strong>to</strong> zero!

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