Multiple choice technology databases

What is the effect of setting the value "ALL_ROWS" for OPTIMIZER_GOAL parameter of the ALTER SESSION command ?

  1. This value causes the optimizer to the rule-based approach for all SQL statements in the session regardless of the presence of statistics and to optimize with a goal of best throughput

  2. This value causes the optimizer to the rule-based approach for all SQL statements in the session in regard of the presence of statistics and to optimize with a goal of best throughput

  3. This value causes the optimizer to the cost-based approach for all SQL statements in the session regardless of the presence of statistics and to optimize with a goal of best throughput

  4. This value causes the optimizer to the cost-based approach for all SQL statements in the session regard of the presence of statistics and to optimize with a goal of best throughput
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The ALL_ROWS optimizer goal in Oracle instructs the optimizer to use cost-based optimization and minimize total resource consumption (best throughput) for the entire result set. However, this option is incorrectly phrased - CBO does require statistics to function optimally, and there's a grammatical error in option C.

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