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Unformatted text preview: HE view is less than 0.9.
A: You don't need to tune SQL statements in application when the GETHITRATIO in the
V$LIBRARYCACHE view is ABOVE 0.99.
B: Application does not require tuning when the misses in the dictionary cache are greater than
1% of the hits. Correct formula for hit ration is : SUM(GETS - GETMISSES) / SUM(GETS) *
D: It's good for performance when the ratio of RELOADS to PINS in the V$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
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
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.
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
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.
Oracle Library Cache as part of SGA will NEVER allocate memory...
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This document was uploaded on 03/08/2014.
- Fall '09