Because You Know It’s All About the Grain


The most important question to answer when designing a fact table is to determine what the grain of the transaction you wish to record is. Quite literally, it’s all about the base grain. If you select too high of a grain, the you lose your ability to drill down into more detailed analysis. If you…

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Just the Facts, Jack!


While we’ve previously discussed the importance of determining the grain of your fact table, we really didn’t cover exactly what data elements should go into the table. One of the reasons much of this site will concentrate on dimensions is because the dimensional data keys are integral to the fact table build. Once you determine the…

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I’m Sorry, You’re Just Not My Type 1 Data…


Type 1 data is something you’ll hear frequently when talking about OLTP (OnLine Transactional Processing) systems, and it can be common within a data warehouse as well. What is it? Type 1 data is essentially a permanent “current record” within a dimension. When a change occurs to a dimensional record, the change overwrites the previous…

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I’m Looking for More of a Type 2


We covered Type 1 Data in a previous article. So now that you know what Type 1 data is, what is Type 2? Also known as a slowly changing dimension (SCD), Type 2 dimensions simply are dimensional records that represent a unique value at a specific and unique point in time.  The key advantage to this…

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