Archive for the ‘10gR2’ Category
Thursday, May 29th, 2008
Recently I was reading this thread, "Trying to make use of bitmap indexes" on the Oracle Forum. Before I had finished a working example, Jonathan Lewis had posted his response which was on par with my thoughts. Since this is a topic I see frequently, I thought ...
Posted in 10gR2, 11gR1, Data Warehousing, Execution Plans, Optimizer, Performance, SQL Tuning, Statistics, Troubleshooting, VLDB | 6 Comments »
Thursday, May 22nd, 2008
Recently someone showed me a query execution plan with an operation of HASH JOIN ANTI NA. At first, it was thought maybe it was a bug and the operation had a type-o in it, but after further research it was discovered it was a valid operation and a new ...
Posted in 10gR2, 11gR1, Data Warehousing, Execution Plans, Optimizer, Oracle, Performance | 7 Comments »
Wednesday, March 26th, 2008
Recently the Oracle Optimizer Development Team put out a White Paper entitled Upgrading from Oracle Database 9i to 10g: What to expect from the Optimizer. This paper discusses the main differences between 9i and 10g in the subject area of the Optimizer and Statistics. As G.I. Joe ...
Posted in 10gR2, Execution Plans, Optimizer, Oracle, Statistics, Troubleshooting | 16 Comments »
Wednesday, March 5th, 2008
I recently came across a query in which the Optimizer was making a poor cardinality estimate, which in turn caused inefficient join type, which in turn caused the query to run excessively long. This post is a reenactment of my troubleshooting.
The Suspect SQL
The original SQL was quite large ...
Posted in 10gR2, 11gR1, Data Warehousing, Execution Plans, Optimizer, Oracle, Performance, SQL Tuning, Statistics, VLDB | 11 Comments »
Wednesday, January 2nd, 2008
I've been working on a few test cases and I'm in search of some real-world data. If your production Oracle database uses system statistics, either Workload Statistics or Noworkload Statistics, and you are willing to share them, please post a comment with the output from the following two ...
Posted in 10gR2, 11gR1, Execution Plans, Optimizer, Oracle, Performance, SQL Tuning, Statistics | 29 Comments »
Monday, September 17th, 2007
Many of you are aware of the Oracle 11g Database New Features and while some may be generally interested in new features, one area that I focus on is new features that yield gains in performance. Some of these features can be found in the General Server Performance section ...
Posted in 10gR2, 11gR1, Data Warehousing, Optimizer, Oracle, Performance, Statistics | 15 Comments »