Hello there again!
Wednesday, October 5, 2011
Hello there again!
I have been getting a lot of feedback recently from people who are new to OBIEE. One of the most common thing that I am getting is that there are too much information out there for OBIEE and it is too difficult to make sense if you have no OBIEE hands-on experience prior. This is very true. The Internet is a great place to find knowledge and resource for whatever you want, but the amount of information you can find online can be overwhelming if you don't have any Insight experience of what you are learning, it is a place where people can get lost.
If you look at the subject of OBIEE, you know there is a lot for you to read. There is the Admin guide, user guide, installation guide and all kinds of other guides. Each talks about a different subject, sometimes they seem to be all related but more often they are not. If you haven't used the tools, haven't seen it, you will get lost just by reading these documents. Or it will take lots of time and hard work to get the knowledge. Therefore, I am trying to come up with an easier way for beginners to shortcut through the obstacles they might be facing in their learning. I am not saying not to read Oracle's document, but I am hoping that this article will help you make your understanding of those documents better and more effortlessly. This is an '101' for OBIEE, if you already know your way around the tool, you can still enjoy this article as it might give you a different perspective.
Anyways, my belief in doing what we do in life has to do with 3 aspects: What to do, how to do and why to do. For any people successful at what they do, they usually let 'why to do' to be the guide, which drives the rest of their actions. The same thing applies in understanding OBIEE. If you want to shortcut your learning curve, the best place to start with is to understand 'why we need OBIEE' or 'What is OBIEE trying to achieve?' To know the Why, you can read it here.
Let me just briefly explain what OBIEE is trying to achieve as an output from a technical perspective. You see, the predecessor of OBIEE is Siebel Analytic or NQuire even before. It was basically a tool that generates a SQL query to send to the relational Database and posts the query result at the UI where users can see it. OBIEE has taken this tool and added more features to it to do the job better and more flexibly. However, it doesn't change the fundamental of this application. Therefore, when you think of OBIEE, always remember that the output of your design and configuration is to produce an SQL Select statement, and the result of this output is the reports that you can publish on dashboard.
So having the above understanding, lets go look at 'how' OBIEE does it. Of course, as I am writing this article, I am assuming most of my readers have SQL knowledge and understands data modeling concepts. If you don't, then make this your first 'Why' to handle before you even think about learning OBIEE. Enough said here.
In order to produce the SQL select statement that meets the requirement, you have to know what you are selecting; from what tables or objects you are selecting from; where are the filtering conditions or joining conditions that applies to this statement. This is the basic elements that any select statements must have if selecting from multiple tables. Therefore, the way OBIEE does it is to use an application called 'Admin tool'. --- Now you can go read Oracle's Admin tool guide already knowing what it is here for, it will make your learning a lot more solid.
Anyways. the Admin tool upon entering looks like this (with explanation of each of the 3 layers):
If your client has purchased the OBIEE's pre-built model, such as BI Apps, Admin tool will look at the following upon login:
Now, you can go back to Oracle's Admin guide and read more about what you can do in each of the 3 layers in your design process.
For best practices, try to keep standard star-schema in your design. If you want to know more about the difference between joins in physical layer VS joins in BMM Layer, read this.
So, now that the design is finished as we have done our things from physical layer to BMM layer and rename the fields in business terms in presentation layer, we can save everything we have done in Admin tool. So all of the objects that we have saved are stored as an 'rpd' or repository. So if you ever come across the term Rpd file in any of the documents you read, you will know what they are talking about. Repository is a filed with '.rpd' at the end, it is saved in OBIEE's directory under 'repository folder'. The essence of 'production migration' is nothing but to copy the .rpd file from your design environment to the same folder within OBIEE directory on production environment. The 'how to do it' varies from company to company, but if you know the 'why', you can easily pick up the 'how'.
So moving on, we have done our design of data modeling, the next step is to create reports based on the design we have done in Admin Tool. This takes us to a different place: presentation service. Ok, in OBIEE 10g, we have one server (BI server) that controls the operation and connection between repository and the DB, and another server (presentation server and OC4J) that controls the operation of the UI of presentation service. 11G has changed the architecture by introducing weblogic. You can read more about the architecture of 10G vs 11G, Oracle has a few good documents and internet has some great articles about it too. I will skip that in this article.
Just to make it easier for beginners to understand, the way to get into the presentation service is by using a 'url link'. Every client has a different link, it is usually provided upon installation. Depending on the name of the server where OBIEE is installed, the url is different. For beginners, don't worry about those things. Just access the link that's provided by your admin and log on!
Of course the UI interface of 11g and 10 are very different. But it still work the same way. What you will see is a list of 'Subject Areas', which is the presentation folders you have designed in presentation layer. By clicking on the subject area, it takes you to a list of folders and columns that's within the subject area. All these are the exact same thing as your design in presentation layer. These are the objects users and report developers use to create their reports.
So upon knowing what it is and why we use presentation service/dashboard, go and read the Presentation service user guide for more details on how to create reports, how to use filters and prompts, how to customize fields and how to make reports and dashboard interactive.
This is good for now.. I hope this article gives you a good focus on where to start and where to follow at the beginning of your OBIEE learning journey. If you understands the BI concept and every thing that this article mentions, I will say you have built a pretty solid foundation. Of course, the best thing to do in order to get better is by practicing. Try it out in your testing environment, build some simple data schema and create some reports. Have fun with it.. Go back and ask yourself what if you want to see certain fancy stuffs, what if there is strange scenarios? What would you do? Use your imagination and creativity and keep exploring the answers!
Until next time