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Oracle Tips by Burleson |
OCP Instructors Guide for
Oracle DBA Certification
Chapter 8 -
Miscellaneous Oracle Information
Oracle9i – Flashback
Query
Remember, although flashback query is promising to be a beneficial
feature in Oracle9i, it is not a panacea. Applications should not be
designed to depend upon flashback query data. In addition, although
it may prevent an occasional database recovery, it must be used
cautiously. If data has been changed incorrectly, administrators
must determine if other transactions have used that incorrect data
as input. If the transactions using incorrect data as input have
also made data changes, bad data is now being propagated throughout
the database. It may be safer to perform a database recovery to a
previous point in time.
The Oracle Database Fundamentals I (1Z0-031)
certification test will have a few questions the new Flashback Query
feature provided in Oracle9i. Test candidates should understand:
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The basics of the Flashback Query feature and
the benefits it provides
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The feature’s reliance upon automated undo
management and the importance the undo_retention parameter
has on Flashback Query
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How to use the DBMS_FLASHBACK package
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The impact DDL changes have on Flashback Query
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The use of the AS OF specification in SQL
queries to activate the Flashback Query feature
The above text is
an excerpt from:
OCP Instructors Guide for Oracle DBA Certification
A Study Guide to Advanced Oracle Certified Professional Database
Administration Techniques
ISBN 0-9744355-3-8
by Christopher T. Foot
http://www.rampant-books.com/book_2003_2_OCP_print.htm
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