9 incorrect answers a you dont need to tune 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: HE view is less than 0.9. Incorrect Answers: A: You don't need to tune SQL statements in application when the GETHITRATIO in the V$LIBRARYCACHE view is ABOVE 0.99. B: Application does not require tuning when the misses in the dictionary cache are greater than 1% of the hits. Correct formula for hit ration is : SUM(GETS - GETMISSES) / SUM(GETS) * 100. D: It's good for performance when the ratio of RELOADS to PINS in the V$LIBRARYCACHE view is less than 0.01. Actualtests.com - The Power of Knowing 1Z0-024 Oracle 8, DBA Certification Exam Guide, Jason S. Couchman, p. 852-854. Chapter 18: Tuning Memory and Operating System Use QUESTION 26: What are two possible causes of lock contention? (Choose two) A. Uncommitted changes. B. Too many rollback segments.C. Improperly sized redo logs. D. Shared pool is sized too large. E. Other protocols imposing unnecessarily high locking levels. Answer: A, E Explanation: There are two possible causes of lock contention: uncommitted transactions and unnecessary high locking levels. For example, if you update data in an area of the application where users expect to perform queries against the database, you might wind up holding a lock that causes contention. This is because the application probably won't issue a commit any time soon, to release the acquired lock. If process holds an exclusive lock on a table and does not relinquish that lock, then other processes will contend in their attempt to change the same data in the table. Incorrect Answers: B: The large amount of rollback segments will reduce lock contention. C: Size of redo logs cannot cause lock contention. D: Large size of shared pool will reduce lock contention, not increase it. Oracle 8, DBA Certification Exam Guide, Jason S. Couchman, p. 938-940. Chapter 20: Tuning Other Areas of the Oracle Database QUESTION 27: Which component will NEVER allocate memory from the large pool? A. Oracle Library Cache. B. Oracle Parallel Query. C. Oracle Recovery Manager. D. Oracle Multithreaded Server. Answer: A Explanation: Oracle Library Cache as part of SGA will NEVER allocate memory...
View Full Document

This document was uploaded on 03/08/2014.

Ask a homework question - tutors are online