INSIDE THE ORACLE OPTIMIZER - REMOVING THE BLACK MAGIC

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SATURDAY, JULY 31, 2010

We have moved!
You might have been wondering why things had gone so quiet on the Optimizer development team's blog Optimizer Magic over the last few months. Well the blog has moved to blogs.oracle.com/optimizer. All of the old articles have moved too and we plan to be a lot more active at our new home, with at least one new post every month.
POSTED BY OPTIMIZER DEVELOPMENT GROUP AT 10:57 AM 0 COMMENTS
FRIDAY, MARCH 12, 2010

Explain adaptive cursor sharing behavior with cursor_sharing = similar and force.
This post has moved to
http://blogs.oracle.com/optimizer/entry/explain_adaptive_cursor_sharing_behavior_with_cursor_sharing_similar_and_force
POSTED BY OPTIMIZER DEVELOPMENT GROUP AT 5:00 PM 0 COMMENTS
LABELS: CURSOR SHARING
MONDAY, DECEMBER 21, 2009

Upgrading from 9i to 11g and the implicit migration from RBO
This blog post has moved to
http://blogs.oracle.com/optimizer/entry/upgrading_from_9i_to_11g_and_the_implicit_migration_from_rbo
POSTED BY OPTIMIZER DEVELOPMENT GROUP AT 3:26 PM 0 COMMENTS
TUESDAY, NOVEMBER 17, 2009

What should I do with old hints in my workload?
This blog post has moved to
http://blogs.oracle.com/optimizer/entry/what_should_i_do_with_old_hints_in_my_workload
POSTED BY OPTIMIZER DEVELOPMENT GROUP AT 3:05 PM 0 COMMENTS
LABELS: SQL PLAN MANAGEMENT, UPGRADE
WEDNESDAY, OCTOBER 28, 2009

Oracle Open World 2009 Summary
We had a great time talking to our users at Open World 2009 both at our Demogrounds booth and at our two sessions. We received a lot of interesting questions during the Optimizer Roundtable discussion, but we did not get to answer all of them due to time constraints. We plan to address the questions we received (both answered and unanswered) in future blog posts... so stay tuned. If you didn't get to attend the discussion, but have a question about the Optimizer, submit it through the email link above.

For those of you who did not get a chance to stop by our Demogrounds booth, here's a recap of the new features that we talked about. Many of the topics have already been covered in earlier blog posts.
Enhanced bind peeking with Adaptive Cursor Sharing: Read about Adaptive Cursor Sharing and a followup.

Faster and more accurate Statistics gathering: Read about our new statistics gathering algorithm in 11g and incremental maintenance of global statistics for partitioned tables.

New types of Statistics that improve cardinality estimates

Ability to gather but not publish Statistics

Guaranteed plan stability and controlled plan evolution: Read about SQL Plan Management.

New tools to help correct regressed execution plans: Read about our Plan Diff tool and Test Case Builder.

These topics are focused on well-known pain points from earlier versions of Oracle. But we also have plenty of new optimizations in Oracle 11gR1 and 11gR2. Stay tuned for details about some of our new optimizations.
POSTED BY OPTIMIZER DEVELOPMENT GROUP AT 11:09 AM 0 COMMENTS
LABELS: OPEN WORLD
FRIDAY, OCTOBER 9, 2009

Open World Recap and New White papers
The Optimizer group has two session and a demo station in the Database campground at this year's Oracle Open World. We will give a technical presentation on What to Expect from the Oracle Optimizer When Upgrading to Oracle Database 11g and host an Oracle Optimizer Roundtable.

The technical session, which is on Tuesday Oct 13 at 2:30 pm, gives step by step instructions on how to use the new 11g features to ensure your upgrade goes smoothly and without any SQL plan regressions. This session is based on our latest white papers, Upgrading from Oracle Database 10g to 11g: What to expect from the Optimizer and SQL Plan Management in Oracle Database 11g.

The roundtable, which is on Thursday Oct. 15th at 10:30 am, will give you a first hand opportunity to pose you burning Optimizer and statistics questions directly to a panel of our leading Optimizer developers. In fact if you plan to attend the roundtable and already know what questions you would like to ask, then please send them to us via email and we will be sure to include them. Other wise, you can hand in your questions at our demo station at any stage during the week, or as you enter the actual session. Just be sure to write your questions in clear block capitals!

We look forward to see you all at Open world.
POSTED BY OPTIMIZER DEVELOPMENT GROUP AT 12:32 PM 0 COMMENTS
LABELS: OPEN WORLD
TUESDAY, SEPTEMBER 1, 2009

What's Changed between my New Query Plan and the Old One?
This blog post has moved here
http://blogs.oracle.com/optimizer/entry/whats_changed_between_my_new_query_plan_and_the_old_one
POSTED BY OPTIMIZER DEVELOPMENT GROUP AT 1:21 PM 1 COMMENTS
LABELS: DIAGNOSABILITY TOOLS, UNDERSTANDING EXECUTION PLANS
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The views expressed on this blog are our own and do not necessarily reflect the views of Oracle and its affiliates. The views and opinions expressed by visitors on this blog are theirs solely and may not reflect ours.
UPCOMING EVENTS & PRESENTATIONS

Oracle Open World, the largest gathering of Oracle customers, partners, developers, and technology enthusiasts will happen October 2-6 in San Francisco. Of course the Optimizer development group will be there and you will have multiple opportunities to meet the team, in one of our technical sessions, or at the Oracle demogrounds.

This year the Optimizer team has 3 technical sessions;


Monday, October 3rd at 12:30pm our hands on lab, Oracle Optimizer: Prevent Suboptimal Execution Plans
Session 29380 at the Marriott Marquis - Salon 12 / 13
In this hands on lab you will get an opportunity to solve 4 SQL tuning problems either on your own or with the help of the Optimizer development team. The problems will include scenario like, why was my index not selected, why statistics were ignored, and many more.

Wednesday, October 5th at 10 am Oracle Optimizer: Best Practices for Managing Optimizer Statistics
Session 13961 at Moscone South - room 103
In this session we will discuss the features introduced in Oracle Database 11g to improve the quality and efficiency of statistics-gathering as well as strategies for managing statistics in various database environments.

Thursday, October 6th at 12 noon Oracle Optimizer: Tips for Preventing Suboptimal Execution Plans
Session 14069 at Moscone South - room 104
This session is a continuation from a session we did last year called Top Tips for getting optimal SQL execution every time. This year we answers questions like why an index wasn't used, why partition eliminations did not occur, why statistics were ignored, and many more. With clear how-to examples, you will learn to identify and quickly resolve these issues without the need for optimizer hints or
initialization parameters.
If you have some burning Optimizer or statistics related questions, you can ask them at the Optimizer demo booth in the Database area of the demogrounds. Members of the Optimizer development team will be there Monday to Wednesday from 9:45 am until 5:30pm. The full searchable OOW catalog is on-line, or you can browse the speakers by name. So start planning your trip today!

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introduction (1)
open world (5)
optimizer statistics (3)
query optimization (2)
sql plan management (5)
understanding execution plans (2)
upgrade (2)
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