Hotsos Symposium Speaker – Martin Hoermann
Mr. Hoermann is a new Hotsos Symposium presenter.
Biography
Martin Hoermann has had a consultancy for ten years with ORDIX for various customers in Germany. His subjects are Oracle, BMC Patrol, and Informix. In the past, he has presented at the German Oracle User Group (DOAG - Deutsche Oracle Anwender Gruppe). Further Oracle presentations have been to the German Unix User Group, HP-User Group and Special Interest Groups (SIG) Database events and conferences. Martin Hoermann has also been holding seminars on Oracle Administration, SQL, PL/SQL, Tuning and RAC for more than eight years.
Presentation Title
SQL Performance on RAC: Pirates of the Interconnect
Abstract
Moving from Oracle Parallel Server (OPS) to Real Application Cluster (RAC) raises hopes of having a cluster database for every kind of application without further needs of customizing the application itself. In fact, we have seen a lot of applications running slower on RAC than on single instance databases.
This presentation will focus on the aspects of SQL programming and its implications on the performance of RAC databases.
The understanding of RAC global cache, architecture of cache fusion and interconnect metrics will lead to an understanding of what kind of SQL statements will affect the performance on RAC in general or probably downgrade it. By analyzing the root cause of performance problems, we will get a better understanding of how to solve these specific kinds of problems.
Based on AWR-reports and clinical scripts this presentation examines the usage of:
- Sequences
- Inter-Instance Reads
- Full Table Scans
And, how one or more of the following techniques can resolve performance issues:
- Sequence Caching
- Free List / Free List Groups versus ASSM
- PCTFREE
- Serial Full Table Scans versus Parallel Full Table Scans (direct path reads)
- Logically Separation of Applications / Instance Assignment
For a detailed explanation of the performance analysis, this presentation will also give an overview of certain gv$-Views (especially gv$bh) and some of the gc-wait events and gc-statistics.
Presentation Materials
Presentation materials are available to attendees only. Attendees may find Mr. Hoermann's paper on Hotsos' portal. His presentation has also just been added to the Hotsos portal. Log in using the link in the upper right corner.
Schedule
The speaker schedule can be found at the following links:
