The difference between using logical columns and physical columns in derived columns calculations

When you define a calculated measure column using a logical column, OBIEE performs the aggregation for the columns used in the calculation first, before applying the calculation.

So for example, if a calculated measure (Total Revenue) is derived from the product of two LOGICAL columns (Unit Price x Number of Items), then OBIEE will create SQL such that the Unit Price and Number of Items columns are aggregated first, and then the multiplication.

However, if the calculated measure is derived from the product of two PHYSICAL columns, then the multiplication will be executed first, and then the aggregation after.

This can make a difference in some cases, so know what you want to accomplish and then carefully choose the appropriate column type for your derived column.


OBIEE Best Practices – a collection of resources

There is a lot of great information out there on the web about OBIEE Best Practices.  In this post I create a collection of various blog posts and articles about Best Practices that I have come across.  Some of these are from some of the most popular OBIEE authors/bloggers.  They have done an awesome job sharing their thoughts and advice on various topics.

Reading through these will surely enhance your knowledge about many of the Best Practices for implementing and maintaining an optimal OBIEE environment.  If you come across other great “OBIEE Best Practices” articles, send me a note and I will add it to this list.

Debashis’s OBIEE Blog: OBIEE Best Practices.  He lists best practices for the RPD development (all 3 layers), Report Design, Security, and Performance.

A presentation (in pdf format) about OBIEE Deployment & Change Management Best Practices

555obiee Blog: OBIEE Caching Best Practices

Rittman Mead presentation (in pdf format): OBIEE Systems Management & Best Practices

A white paper on … Best Practices for Tuning OBIEE (applies to versions and

allaboutobiee Blog: OBIEE Best Practices – Presentation Layer

allaboutobiee Blog: OBIEE Best Practices – BMM Layer

allaboutobiee Blog: OBIEE Best Practices – Physical Layer

bidirect Blog: Dashboard Tips and Best Practices

biometrics Blog: OBIEE Best Practices

Peak Indicators: 20 Golden Rules for OBIEE 11g RPD Design  or to go directly to the pdf: 20 Golden Rules for OBIEE 11g RPD Design (pdf)

obieeexpress Blog: OBIEE Presentation Services Best Principles/Practices

oracletechnotalk Blog: Physical Layer Best Practices in OBIEE

varanasisaichand  Blog: Dimensional Hierarchies Best Practices

nerdsofobiee Blog: BI Best Practices. This article focuses on the view of the Business, and discusses items such as dashboards, communication with/involvement of business users on projects, and ease of use.

Rittman Mead: Data Modeling Tips

Rittman Mead: Data Modeling Best Practices

obiee101 Blog: OBIEE Golden Rules by John Minkjan

Changing the name of a Subject Area in OBIEE 10g (in preparation for upgrade to 11g)

This article shares a few steps for renaming a “Subject Area” in OBIEE 10g.  OBIEE 10g allowed leading spaces in Subject Area names. You may have done this to alter the sort order of your Subject Areas without using leading numbers. This would result in only a Warning message when you checked the repository’s consistency.  However, leading spaces in Subject Area names is not allowed in OBIEE 11g, and will result in an Error.

So, if you are upgrading to OBIEE 11g then you will need to change the Subject Area name(s) to remove leading spaces or you may need to change Subject Area name(s) for other reasons.

Here are a few steps to consider but I recommend that you perform these steps for one subject area first, confirm all is well, then repeat steps for all subject areas.

  1. Stop the Presentation Server.
  2. In the Oracle BI Administration Tool, manually rename the Subject Area(s) in the Presentation Layer (and remove the leading spaces if that was the reason for the rename).
  3. Log into Catalog Manager in online mode, and navigate to Tools –> XML Search and Replace
  4. Carefully set the text you would like to replace with the new text – but make sure the text string is unique enough so that you do not inadvertently changed text that you don’t want to change.  Repeat for each name change that is required.
  5. You may need to manually open your prompts in Answers to change the Subject Area names in the custom SQLs used to generate defaults and drop down lists.
  6. Restart the Presentation Server and test your changes.