Skip to main content

Creating Mondrian Star Schemas with Power*Architect - Part 1/2

A few months ago I first mentioned that you can create Mondrian schemas with Power*Architect. Finally I get the time to create a step by step guide for a small Mondrian schema. This post covers the preparation of Power*Architect to create a new schema, the coming blog post will cover the schema creation and testing.


What you need to get started:
Step 1 - Setting up the database connection
  • Start Power*Architect
  • Open the Connections menu and start the Database Connection Manager.
  • Click on New.
  • Add the database connection details. For the Pentaho sample data enter the data as shown in the screenshot (Click on it for a larger screenshot). Make sure you enter the right folder name.

  • Test the connection and click on Ok.
  • Close the Database Connection Manager.
  • Open the Connections menu -> Add source connection and select the created connection
Step 2 - Visualize the data model (Optional)

If you don't know the data model, I recommend using Power*Architect to visualize it. This step is not needed for the creation of Mondrian schemas.
  • Unfold the database connection and drag&drop the needed tables to the right hand PlayPen. In my example I use the tables orders, customers, dim_time and orderfact.
  • Add the relationships between the tables: Click on (Non identifying relationship), on the key in the dimension table and then on the related column in the fact table.
  • Add the end the model should look similar to the following screenshot.

  • You can find more details on how to use Power*Architect in the help and manual.
The second part tomorrow will cover the actual schema creation and testing. Comments are welcome.
Labels:

Comments

Post a Comment

Popular posts from this blog

Pentaho Data Integration - Multi-part Form submission with file upload using the User Defined Java Class Step

I recently needed to use Pentaho Data Integration (PDI) to send a file to a server for processing using HTTP Post. I spent several hours trying to use the existing steps HTTP Post, HTTP Client & Rest Client but I couldn't get it to work. After some more research I came across the issue PDI-10120 - Support for Multi-part Form Submittal In Web Service Steps  and I thought I was out of luck. I previously wrote a small Java client for a similar use case and remembered the PDI has a step called User Defined Java Class  (UDJC). After reading this great tutorial I created the following basic transaction. I have a dataset with the URL and the full file path and use the UDJC to make the HTTP call. HTTP Post using User Defined Java Class The Java class handles the actual HTTP Post. It uses 2 input variables, the URL (url) which is used for the call and the file name (longFileName). The HTTP call then contains the file (line 30) and the file name (line 31). I included some basi
7 comments
Read more

Products you don't expect to be 'Made in China' - Del Monte fruit cups

Since I moved to Canada back in March I have started to realize how many products are actually made in China. Back in Germany you could also buy lots of stuff from China but you mostly had the choice between German or Europe products and Chinese products. When I went to Food Basics in Oakville a couple weeks ago to get some apples I stood in front of a huge tray of Chinese apples! Aren't there enough apples in Ontario, Canada or the US? Even Mexico would probably be closer than China. Another day my wife bought Del Monte fruit cups in the grocery store. I checked the label when I was going to eat it and i decided to leave it in the fridge. First of all it is 'Made in China' (again I guess no other country in this world has fruit) and second it contains artificial flavor. How bad must the fruit inside be that you need artificial flavor (and does anybody in China controls how it is made)? For my part I'll check the labels more closely whenever I buy any kind of product
Post a Comment
Read more

Creating YTD transformation tables

The other day I had to setup a new data warehouse that will be used for reporting with MicroStrategy. Part of it was setting up the date dimension including the transformation tables. I had a quick look online and couldn't find any script doing the work for me so I created them myself (with the help of a colleague). All you need is an existing date dimension with date_id, year_id, quarter_id, month_id and week_id, you can find plenty of scripts for that online. YTD table select t1.day_id, t2.day_id INTO YTD_DAY from LU_DAY t1, LU_DAY t2 where t1.day_id >= t2.day_id and t1.year_id = t2.year_id QTD table  select t1.day_id, t2.day_id as qtd_day_id INTO QTD_DAY from LU_DAY t1, LU_DAY t2 where t1.day_id >= t2.day_id and t1.QUARTER_id = t2.QUARTER_id  MTD table select t1.day_id, t2.day_id as mtd_day_id INTO MTD_DAY from LU_DAY t1, LU_DAY t2 where t1.day_id >= t2.day_id and t1.month_id = t2.month_id  WTD table select t1.day_id, t2.day_id as wtd_day_id INTO WTD_D
Post a Comment
Read more