Contents
What kind of measures are facts in a fact table?
The primary key of a fact table is usually a composite key that is made up of all of its foreign keys. Fact tables contain the content of the data warehouse and store different types of measures like additive, non additive, and semi additive measures.
What are dimension attributes?
A dimension attribute is a column in a dimension table. Each attribute describes a level of summary within a dimension hierarchy. Because dimension attributes describe the items in a dimension, they are most useful when they are text.
What is the difference between dimension and attribute?
As nouns the difference between attribute and dimension is that attribute is a characteristic or quality of a thing while dimension is a single aspect of a given thing.
Is date an attribute or measure?
1 Answer. Date fields are only treated as dimensions by default, but you can certainly use a date as measure instead. Measures are aggregated in Tableau, so you would normally compute the max (i.e. latest) date value, or the min (i.e. earliest) data value, or perhaps the count or distinct count of a data field.
What makes a fact table a dimension table?
In the dimensional modeling world, we try very hard to separate data into two contrasting camps: numerical measurements that we put into fact tables, and textual descriptors that we put into dimension tables as “attributes”. If only life were that easy…
How to model data as both a fact and dimension?
Include the limit in the coverage dimension so that it participates in the usual way as a target for constraints and the content for row headers, but also put the limit in the fact table so it can participate in the usual way within complex computations. This example illustrates some important dimensional modeling themes:
How are dimension attributes different from fact attributes?
Dimension attributes, on the other hand, are the targets of constraints, and provide the content of “row headers” (grouping columns) in a query. While probably 98% of all data items are neatly separated into either facts or dimension attributes, there is a solid 2% that don’t fit so neatly into these two categories.
How do I add a measure to a fact table?
In the Fact Tables area, click the fact table for which you want to create measures. In the Columns area, click Add Column. In the New Column editor, enter a name and description for the column.