Have you ever tried to delete a few million rows from a table with several hundred milllions of rows with a DELETE statement? If yes, then you know that this is a very bad idea. With Oracle Partitioning you can do this more elegant and much faster.
PL/SQL functions in SQL statements may cause major performance problems. If it is not possible to avoid these calls, there are several solutions to improve the performance. But not for all situations.
An almost unknown simplification in the usage of dbms_xplan is possible since Oracle 12.2. Sometimes, there are small details that makes our job (a little bit) easier.
Hash keys can be used instead of sequence numbers to build surrogate keys in a Data Warehouse. This is often done in Data Vault environments, and there are some good reasons to do that. But there are also several issues and restrictions with hash keys. So, use hash keys only if you have good reasons for them. And if you decide to use hash keys in your Oracle Data Warehouse, make sure that you do it the right way.
Dynamic SQL is a wonderful feature with a lot of flexibility. Unfortunately, it is not trivial to see the executed SQL statements. A simple trick helps to test and debug PL/SQL code with Dynamic SQL.
Oracle Warehouse Builder (OWB) is at the end of its lifecycle. The ETL tool will not be supported by Oracle in the future. But many customers have built data warehouses with OWB. What can they do with their existing OWB projects? A Trivadis white paper describes different migration scenarios.
The Oracle OpenWorld 2014 just finished yesterday, but unfortunately I was not able to attend this great conference this year. Perhaps next year – who knows…
But I had the luck to give several presentations in the last few years on Oracle OpenWorld in San Francisco, on the DOAG Conference in Nuremberg and on some other German conferences. Now you can find all these presentations on SlideShare. Because most of the slides are not brand new, my Trivadis colleague Silvana Bernasconi reformatted the older presentations to the current Trivadis PowerPoint template (thank you, Silvana). Nevertheless I promise: The contents of all these presentations is still up to date. Enjoy to have a look at and probably download some of the presentations.
An overview of all my presentations you can find on the Presentation page.
Last week I got an interesting question from a former colleague: How can interval partitioning in Oracle 11g be combined with partition exchange?
In the Moscone West building at the OpenWorld, there is a bookstore full of Oracle books (they also have Oracle teddy bears, Oracle T-shirts, Oracle bags, Oracle water bottles and other advertising stuff). I spent some of my rare spare time between the sessions to grub in many interesting books.
Data Warehousing with Oracle 