Describe Power BI Desktop Model

 Star schema design

1. Facts Table

The role of a fact table is to store an accumulation of rows that represent observations or events that record a specific business activity. 

Facts :
Model purpose -It stores events or observations
Table structure -Includes dimension key columns and numeric measure columns that can be summarized
Data volume - Typically, contains fewer rows
Query purpose - To filter and group

2. Dimension Table

Dimension tables describe our business entities, which commonly represent people, places, products, or concepts. A date dimension table, which contains one row for each date, is a common example of a concept dimension table. The columns in dimension tables allow filtering and grouping of fact table data.

Facts: 

Model purpose -It stores business entity
Table structure - Includes a key column and descriptive columns for filtering and grouping.
Data volume - Typically, contains fewer rows
Query purpose - To filter and group

Analytic Queries -

An analytic query is a query that produces a result from a data model. Each Power BI visual, in the background, submits an analytic query to Power BI to query the model. The analytic query is written as a Data Analysis Expressions (DAX) query statement.

An analytic query has three phases that are implemented in the following order:

  1. Filter

  2. Group

  3. Summarize

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