READ Free Dumps For Oracle- 1z0-060
| Question ID 20797 | Which three features work together, to allow a SQL statement to have different cursors for the same statement based on different selectivity ranges?
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| Option A | Bind Variable Peeking
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| Option B | SQL Plan Baselines
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| Option C | Adaptive Cursor Sharing
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| Option D | Bind variable used in a SQL statement
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| Option E | Literals in a SQL statement
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| Correct Answer | A,C,E |
Explanation Explanation: * In bind variable peeking (also known as bind peeking), the optimizer looks at the value in a bind variable when the database performs a hard parse of a statement. When a query uses literals, the optimizer can use the literal values to find the best plan. However, when a query uses bind variables, the optimizer must select the best plan without the presence of literals in the SQL text. This task can be extremely difficult. By peeking at bind values the optimizer can determine the selectivity of a WHERE clause condition as if literals had been used, thereby improving the plan. C: Oracle 11g/12g uses Adaptive Cursor Sharing to solve this problem by allowing the server to compare the effectiveness of execution plans between executions with different bind variable values. If it notices suboptimal plans, it allows certain bind variable values, or ranges of values, to use alternate execution plans for the same statement. This functionality requires no additional configuration.
| Question ID 20798 | You notice a performance change in your production Oracle 12c database. You want to know which change caused this performance difference.
Which method or feature should you use?
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| Option A | Compare Period ADDM report
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| Option B | AWR Compare Period report
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| Option C | Active Session History (ASH) report
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| Option D | Taking a new snapshot and comparing it with a preserved snapshot
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| Correct Answer | A |
Explanation