B you can only have one stored outline per sql

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: egories. B. You can only have one stored outline per SQL statement. C. Plan stability works only when SQL statements match. D. Stored outlines are saved in the data dictionary (SYS schema) E. Stored outlines become invalid when you analyze the associated objects. Answer: A, C Explanation: You can group outlines in categories. To use stored outlines you also need to be sure that SQL statements match textually. Reference: Here is explanation about 'plan stability' from Metalink: Oracle9i Database Performance Tuning Guide and Reference Release 2 (9.2) Part Number A96533-02 Chapter 7 "Using Plan Stability" "Plan stability prevents certain database environment changes from affecting the performance characteristics of applications. Such changes include changes in optimizer statistics, changes to the optimizer mode settings, and changes to parameters affecting the sizes of memory structures, such as SORT_AREA_SIZE and Actualtests.com - The Power of Knowing 1Z0-024 BITMAP_MERGE_AREA_SIZE. Plan stability is most useful when you cannot risk any performance changes in an application. Plan stability preserves execution plans in stored outlines. Oracle can create a public or private stored outline for one or all SQL statements. The optimizer then generates equivalent execution plans from the outlines when you enable the use of stored outlines. You can group outlines into categories and control which category of outlines Oracle uses to simplify outline administration and deployment. The plans Oracle maintains in stored outlines remain consistent despite changes to a system's configuration or statistics. Using stored outlines also stabilizes the generated execution plan if the optimizer changes in subsequent Oracle releases. Plan stability also facilitates migration from the rule-based optimizer to the cost-based optimizer when you upgrade to a new Oracle release." Incorrect Answers: B: It can be more than one stored outline per SQL statement. D: Stored outlines are saved in the OUTLN schema,...
View Full Document

Ask a homework question - tutors are online