Hotsos Symposium Speaker – Karen Morton

Ms. Morton is a returning Hotsos Symposium presenter.


Karen MortonKaren Morton is Director of Education & Services for Method R Corporation, a Cary Millsap company, based in Southlake, Texas. For over 20 years, Karen has worked in information technology starting out as a mainframe programmer, developer, DBA, data architect and now as a researcher, educator and consultant. Having used Oracle since the early 90's, she began teaching others how to use Oracle over a decade ago. She is an Oracle ACE, maintains a blog at, has authored several Oracle training course books, and is a frequent speaker at conferences and user groups.

Karen is an Oracle Ace.

Presentation Title

Managing Statistics for Optimal Query Performance


Half the battle of writing good SQL is understanding how the Oracle Optimizer analyzes your code and applies statistics in order to derive the "best" execution plan. The other half of the battle is successfully applying that knowledge to the databases that you manage. The Oracle Optimizer uses statistics as input to develop query execution plans and these statistics are the foundation of good plans. If the statistics supplied aren't representative you can expect that garbage in will result in garbage out. However, if the statistics are representative, it is more likely than not that the Oracle Optimizer will choose an optimal plan.

This presentation reviews several key areas where "bad" statistics can cause query plans to be sub-optimal. Then, we'll discuss how to choose an optimal stats gathering strategy. This strategy will include how to best use dynamic sampling and when and how to manually set statistics directly versus collecting them. Special attention will be given to plans derived for long running queries (i.e. queries whose run times are minutes or longer).

Presentation Materials

Presentation materials are available online to attendees only. Karen's presentation can be found on the Hotsos portal. Attendees may log in using the porttal ids to download the documents.


The speaker schedules can be found at the following links: