OBIEE Analysis Date Format as 0/0/0 [Solved]

Issue: We recently came across an error where client raised a defect that date comes up as 0/0/0 for some of the records.

Analysis: First we checked the particular records in the EDW target schema. We could see that the records are having date as null in the physical tables.

Cause: The root cause of this defect is that in the physical layer of the RPD for this particular column the nullable flag is not ticked. Since the nullable flag is not ticked, OBIEE expects a value here and substitutes 0/0/0 12:00:00 AM for null values.

The nullable flag property in OBIEE RPD Physical column object.

This could also happen if you manually change the data type from datetime to date. OBIEE imports date as datetime by default.

Resolution: Change the data type to datetime and tick the nullable flag. Once done, save and upload RPD to the server. Now clear your cache, reload files and metadata and check again. If that still doesn't change anything then do a restart of your presentation service.

What is the OBIEE RPD File and it's Significance ?

The RPD file or Repository is the heart and soul of an OBIEE instance. We discussed earlier in one of our previous posts that Oracle BI has two kinds of metadata, one that exist in database tables and the other which exists in file format. The RPD file is the one of the OBIEE metadata that exists in physical file format, the other being the presentation catalog. 

What does the OBIEE RPD contain ?

The OBIEE RPD is where all the metadata related to a data warehouse or a data source is stored. It basically contains all the OLAP tables which are used to populate graphs and charts, the physical joins between the data. The star schema design/BMM design which tells the BI Server how OBIEE server should fire the query to the data warehouse/database.

The Repository is mainly composed of three layers:

1.Physical Layer 

 This is where you import all your Data warehouse tables. You create your database connection here along with the credentials to connect to the warehouse schema. You can also specify options like connection pooling, timeout option and various other database parameters.

Here you create Alias Tables for all the tables and define the joins between these tables. The joins defined here are inner joins. You can safely say that things relating to the database resides here. 

2.Business Model and Mapping(BMM) Layer

The BMM layer or Business Model and Mapping Layer is where you define the relation between the tables that you had earlier imported to your Physical Layer. Here you define your BMM diagram,  create hierarchies for your dimensions define complex joins between your database tables, set aggregation for measures.  You can also define complex calculations to facts here, however it is recommended to push all complex calculations to database or during the data load to the data warehouse.

Inside the RPD, arguably this is the most important layer as this is where each business process is defined in a way that OBIEE server understands. It is very crucial that the BMM model is designed properly for a compact BI Analytics implementation.

3. Presentation Layer

The presentation layer is what the end user or the BI Author user would see when they log in to the Analytics. The BI Author or the report developer pulls data from this layer using the web UI. It is important that the dimensions and facts are properly organised in this layer so that somebody developing the report would be able to easily pull in columns and build a report.

RPD Location - You can find the RPD file under the Middleware Home folder in your OBIEE server. The exact location to find the RPD file is as below,

MW_HOME/instance/instance1/bifoundation/OracleBIServerComponent/Repository/

In this folder you will be able to find the Repositories that have been deployed over time. To get the currently used RPD name go to Enterprise Manager > CoreApplication > Deployment Tab.

Which component of OBIEE manages the RPD file ?

It is the OracleBIServer component which comes under OracleBI11g components that handles and communicates to the repository file. Every time a request comes from the Web UI(Presentation layer). The OBIEE server refers to the metadata residing in Repository file to convert the same to a Physical SQL query. The data from the SQL query is sent back to analytics for use in reports.

What does the term RPD file refer to in OBIEE 11g ?

If you are new to OBIEE, you might be wondering what the term RPD stands for. Most developers refer to RPD as the repository file, while some people refer to it as Rapid File Database. There are also other names like Repository Design, Repository Dictionary etc. The truth is that there is no definition for the abbrevation in any Oracle documentation. However the most commonly used definition would be Rapid File Database.

Sample App Lite RPD that comes default with OBIEE Installation.

The RPD file or the repository file is the physical metadata file for OBIEE server where relationship between Datawarehouse tables and their related objects are stored. 

Import Cloudera Impala Tables to OBIEE Repository [Solved]

Recently we had an opportunity to work on a demo where the OBIEE data source was Cloudera Impala. So had to create a new ODBC source to import Impala tables to OBIEE repository. So here are the steps.

First you need to install the ODBC Driver for windows from Cloudera's Page.  Now install the Driver 

Installing is basically a very easy task. Advisable to gracefully stop BI Services before Installing as the Installer might ask you to stop Oracle Application Server.

Check for Sample DSN Conneciton

 Once you are done with ODBC driver installation go to run > ODBC and check if you have an entry named 'Sample Cloudera Impala DSN' to confirm that the driver Installation has successfully completed. 

Now click to add a new System DSN and select Cloudera Impala Driver as seen in the image below,

Select Cloudera Impala Driver from the list of drivers

Next provide connection details to your Cloudera Impala Server as seen below.

Default port for Cloudera Impala is 21050. Once you are done giving the details for the connection click on test to test connectivity as seen below,

 Now go to the OBIEE repository and Import metadata as shown below, Select the recently created Impala ODBC data source and proceed.

 

 

Select the Impala Tables to imported and Click Finish. Check the Physical Layer of the repository to see if the Impala Table has been successfully imported. You can use view data to feature to confirm the connection correctly.  

Table in Physical Layer of OBIEE Repository

 Tags: Big Data Cloudera Impala Server ODBC connectivity with OBIEE and BI Tools.

What are Alias Tables and It's significance in OBIEE Physical Layer

An Alias Table or Alias in OBIEE is a physical table which references to a different physical OLAP/OLTP table as it's source.

Alias tables are often used for Repository development over Physical tables as they have the following properties,

1. Enables reuse of a physical table.
2. Avoids circular joins that can form when importing OLTP source tables.
3. Create self joins between tables, for eg: Manager is also an Employee.
4. Enables to easily identify source tables and adhere to data warehousing naming standards.
5. Makes physical query generated easier to understand.
6. Can override source table's caching properties like Cacheable, Cache never expires and cache persistence time. 

Alias Tables in OBIEE 11g - Example.