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An AMIS Overview of Oracle Database 12c

The presentation used during the highly successful AMIS Oracle 12c Launch Event is online for those who are interested. Enjoy. Special thanks for Thomas Kyte; for allowing me to use some of his pluggable database presentation content. An AMIS Overview of Oracle database 12c (12.1) from Marco Gralike


Those who visit often know what the title means. It’s a very simple yet powerful technique to group data which doesn’t seem appropriate for grouping at first sight.
I learned this very nice tip long time ago but often have to re-think before applying it to SQL or even search for the correct way of doing it when my brains give me denial of service. Recently I needed to do this type of query again and thought I should document the process, so I won’t forget it next time.

12c – parallel_degree_level (control for auto DOP)

I heard JP Dijcks speak at RMOUG in 2012 about a new parameter that would show up in 12c called parallel_degree_level. It’s basically a knob that you can turn to dial up (or down) the calculated DOP when setting parallel_degree_policy=auto. Early on ( auto DOP seemed to vastly overestimate what the DOP should be. In a later version ( it seems to often underestimate what the DOP should be. I’ve said in the past that I thought auto DOP was too hard to control and thus too scary for production systems. I’ve also said that I thought auto DOP was the wave of the future. And I think this parameter alone may make it possible to use this feature in production because it gives us the ability to dial in the level of parallelism that works for our system. So here’s a quick demo:

Upcoming Oracle Events in Canberra (The Show Must Go On)

For those of you who live locally in the Canberra region, there are a couple of key Oracle events coming up. Oracle Database 12c Launch Date: Friday, July 26 2013 Time: 8:30 AM – 1:00 PM Where: Hyatt Hotel 120 Commonwealth Ave Yarralumla, Canberra Details and Registration I’ll be presenting “Simplify Consolidation with Oracle Database […]

12c histograms

There are a few enhancements in 12c that might make a big difference to performance for a small investment in effort. One of the important enhancements comes from changes in histograms – which improve speed of collection with accuracy of results. The changes are so significant that I chose the topic as my presentation at OpenWorld last year.

Extra huge database IOs, part 3

This is part 3 of a number of blogposts about huge Oracle database IO’s.
If you landed on this blogpost and did not read part 1 or part 2, please read part 1 here and part 2 here.

SQL Translation Framework

My favorite new Oracle Database 12c feature is the SQL Translation Framework. The feature grew out of SQL Developer’s ability to translate SQL from non-Oracle RDBMS’s. For example, there is a pre-built Sybase ASE translation package that is designed to translate the Sybase dialect of SQL into Oracle SQL dialect. So that’s what the feature is designed for. But the developers decided to move it to the database and to allow us to write our own translations which opens up a whole world of possibilities.

Oracle WebLogic 12cR2 : ADF, Domains, Clusters and Stuff

Following on from yesterday’s post about these WebLogic 12cR2 articles,

I’ve spent today creating ADF enabled domains and clustered domains on WebLogic 12cR2. That has spawned some new articles that are effectively updates of the old WebLogic  11g and 12cR1 articles.

Wrong Index 2

A couple of days ago I wrote an article about Oracle picking the “wrong index” after an index rebuild, and I mentioned that the sample data I had generated looked a little odd because it came from a script I had been using to investigate a completely different problem. This note describes that other problem, which appeared on the Oracle-L mailing list last month.

Oracle WebLogic 12cR2 and ADF Runtime Installations…

The new versions of the WebLogic 12cR2 and ADF could not have come at a worse time for me. My top priority is learning about the 12cR1 version of the database. Second, is getting to grips with Cloud Control 12cR3. Third on the list is getting up to speed with the changes in WebLogic 12cR2 and ADF. Unfortunately, my personal priorities don’t quite match my work priorities, so WebLogic 12cR2 has moved up the list for a while. As a result, I did some installations last night.