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  Oracle Tips by Burleson

Chapter 1 Oracle Instance Internals Scripts



undo header

This one statistic carries the load for all normal rollback segment header blocks.


This statistic carries information on waits on unused blocks.

Table 1: Wait Classes and Their Definitions

Table 2 shows the actions that are used to rectify block waits based on block types.



segment header

Increase of number of FREELISTs. Use FREELIST GROUPs (even in single instance this can make a difference).

Freelist blocks

Add more FREELISTS. In case of Parallel Server make sure that each instance has its own FREELIST GROUP(s).

Undo Waits

Generally speaking most of these waits are self-explanatory. For example, if you have block waits for undo segments you may need larger rollback segments, if you experience header waits for rollback segments, you may need more rollback segments. This takes care of 6 of the waits shown above.

Sort  waits

Waits for sort blocks could indicate insufficient sort area size or sort segments in the sort tablespace.

The above text is an excerpt from:

Mike Ault’s Oracle Internals Monitoring & Tuning Scripts

Written by the world's top DBA and author of over 20 Oracle books, Mike Ault shares his secrets for Oracle DBA management scripts.  This handy reference is indispensable for all Oracle professionals who must quickly automate and manage their Oracle databases with scripts.

This stellar book comes complete with an online code depot full of over 200 pre-tested Oracle DBA scripts, and covers all areas of Oracle database administration including data files, tablespace, table and index management scripts.  Based on more than 20 years full-time experience, Mike Ault brings his expertise to the public with this fantastic book.  Your time savings from a single script is worth the price of this great book.

Mike Ault is one of the leading names in Oracle technology.  The author of 20 books and hundreds of articles in national publications, Mike was the first popular Oracle author with his landmark book "Oracle7 Administration and Management".  Mike also wrote several of the "Exam Cram" books, and enjoys a reputation as a leading author and Oracle consultant.

Mike started working with computers in 1979 right out of a stint in the Nuclear Navy. He began working with Oracle in 1990 and has since become a World Renowned Oracle expert (in the words of his publisher anyway!) Mike has written 14 Oracle related books, dozens of articles, and has presented at conferences in Europe and the USA. Mike has two wonderful daughters and is kept out of trouble by his wife of 29 years, Susan.

See the Oracle script collection::



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