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Unformatted text preview: al in the buffer cache tuning is minimize physical reads.
B: The buffer cache hit radio is definitely affected by data or application design.
C: The buffer cache hit ratio will degrade with the use of full table scans.
D: There is some amount of db block buffers in the SGA after reaching it the buffer cache will
be degrade, not improve. That's why we use V$RECENT_BUCKET view statistics to find
optimal number of db block buffers in the SGA.
Oracle 8, DBA Certification Exam Guide, Jason S. Couchman, p. 859-873.
Chapter 18: Tuning Memory and Operating System Use
Which two statements regarding OLTP systems are true? (Choose two)
A. Use literals for optimally shared SQL rather than bind variables to keep the overhead of
parsing to a minimum.
B. To avoid the performance load of dynamic space allocation, allocate space explicitly so
tables, clusters and indexes.
C. B-tree indexing is preferred to bitmap indexing, because of locking issues affecting DML
Actualtests.com - The Power of Knowing 1Z0-024
D. Use hash clusters especially on tables that are heavily inserted into, because of the use of
space and the number of blocks that need to be visited.
E. Use application code to enforce business rules instead of constraints, because constraints are
extremely expensive to process.
Answer: B, C
It's better to allocate space explicitly to tables, clusters and indexes in OLTP system to avoid the
performance load of dynamic space allocation. B-tree indexing is preferred to bitmap indexes in
OLTP systems, because of locking issues affecting DML operations. Most of DML operations
related with bitmap indexes will require high-level locking due to low cardinality nature of
bitmap indexes and it will cause performance issues because of high level of DML operations in
A: OLTP works mostly with bind variables due to nature of OLTP system, so it's impossible to
work only with literals.
D: It's not reasonable to use hash clusters for tables with heavy inserts.
E: Constraints are cheaper to process if compare them with business rules in application code.
Oracle 8, DBA Certification Exam Guide, Jason S. Couchman, p. 793-795.
Chapter 18: Tuning Memory and Operating System Use Actualtests.com - The Power of Knowing...
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This document was uploaded on 03/08/2014.
- Fall '09