Tag archive for ‘Dimension Tables’
Sometimes, when you are designing a star schema model, you’ll find yourself in a dilemma. You’ve come up with a beautiful design, right out of the pages of a Ralph Kimball book with 5 dimensions, and 5 measures, and you are on your way to star schema heaven when suddenly the users start asking akward […]
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Mystery or Junk data warehouse dimensions
Sometimes, when you are designing a star schema model, you’ll find yourself in a dilemma. You’ve come up with a beautiful design, right out of the pages of a Ralph Kimball book with 5 dimensions, and 5 measures, and you are on your way to star schema heaven when suddenly the users start asking akward […]
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Wolfram Alpha- Dimensional Generator?
Wolfram research is always doing some interesting things- and now they are aiming at providing an answer machine- they are calling it Wolfram Alpha. Its not a search engine that returns documents related to the inputed search terms- but something that computes answers to a question looking for a factual answer. This is interesting, because […]
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Joining the Dimension Table to the Fact Table- Purchasing Data mart (Part 5)
After we have created the dimension tables and the fact table and populated them with data the final step to getting a star schema is of course to actually join the dimension tables to the fact table. In the datamartist tool we do this with a Join block. Check out the first four parts of […]
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Connecting the dimension table to the fact table- Vendor Example (Part 3)
In parts one and two of this series we introduced our challenge (to make a data mart to analyze the Acme Company’s spending) and showed how the Datamartist tool could import millions of rows of data and then turn it into a fact table we can use in Excel. Now we need to create a […]
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Degenerate Dimensions in Datamarts
Not all dimensions are created equal. Â A typical dimension is defined by a table that holds the reference data that is being joined to the fact data. Â So in the fact table, for example, we have the product ID, or the product code, and in the product dimension table we have a single row for […]
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Dimensional Tables and Fact Tables
One of the secrets to putting together a good set of data marts is the concept of dimensions. There are two key steps being able to analyse your data, and to build a working data mart model.  Build a set of clean, consistent dimension tables that store reference information about your key dimensions like Product, […]
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Data modelling Hierarchies- how to make a dimension
One of the most useful data model structures in a data mart is a Hierarchy (also called a Tree structure). Tree structures let us take a large number of things and organise them in a way that makes sense. More importantly, a tree structure lets us “drill down†into information.  Hierarchy Rules In a simple tree […]

