Hotsos Symposium Speaker – Riyaj Shamsudeen
Mr. Shamsudeen is a prior Hotsos Symposium presenter.
Biography
Riyaj Shamsudeen has over 15 years of experience in Oracle and 14+ years as an Oracle DBA/Oracle Applications DBA. He is currently consulting for New AT&T, specializes in RAC, performance tuning and database internals. He has authored a few articles on topics such as internals of locks, internals of hot backups, redo internals, etc. He also teaches in community colleges in the Dallas area such as at North Lake College and El Centro College. He is a member of the OakTable network.
Presentation Title
Cost-Based Subquery Transformation: concepts and Analysis Using 10053 Trace
Abstract
Sub-queries were transformed heuristically prior to Oracle version 10g. In 10gR2 onwards, sub-queries are rewritten and transformed using various techniques, costs calculated and compared for transformations before a final plan is chosen. This transformation is highly mathematical in nature.
Combinations of transformations include techniques such as predicate pushing, view merging, predicate pull up, subquery unnesting, predicate move around, etc. Optimization techniques to reduce the parsing time are also discussed.
This presentation explores the concepts behind this new feature and shows 10053 traces for various test cases. Performance analysts will be able to understand how the queries are transformed and follow 10053 traces to see cost calculations.
Presentation Materials
Presentation materials are available to attendees only. Mr. Shamsudeen's presentation may be found on the Hotsos portal. Please remember to log in using portal id, not email address.
Schedule
The speaker schedule can be found at the following links:
