Understanding Date - Hierachy Dimension and so on
I am new to OBIEE. I have about 5 years good practise of Discoverer and now I am going to update my knowlegde to the new OBIEE.
I was able to create some nice repository based on some tables and views from my discoverer schema. This was more helpfull to me than the tutorials in the OBE.
But now I have some trouble with the dates, date hierachies in Discoverer were nice and easy, but in OBIEE I am more than confused.
While searching the web and the tutorials, I found a lot of tipps regarding the "ago-function". That looks nice, and I believe that I will try this out, but does not solve my current issue, because I am simply one or two steps before that. What I also see in the tutorials is a "times-table". A real table on the database, containing every date, and nearly all date/time-function values in seperate lines.
But for what? I mean: thats why I have date/time functions. In my Oracle Database.
Do I really need such a table? Should I copy it ouf of the SH-example into my productive-database? If yes, why?
In discoverer I simply click on "date hierarchy" and then I got my columns for year, month, quarter and day.
I understand how to create a dimension in the repository, based on some columns.
But when I only have one date column, and this might also contain some time information, what is the best solution here?
And then in practise: I have a view containing my sales data: order, item_id, customer_id, qty, amount, and hand full of dates:
- booked date -> when the order was booked
- request date -> when the customer wants to have the stuff
- shipping date -> when we send the stuff
How should I handle this. Should I then join all these dates with the times table?
I will be thankful for any helpfull links and more detailed explaination.