Microsoft Power BI Cookbook

Identify expensive columns and quick wins

1. Retrieve and analyze the memory consumed by the columns of the largest fact table or tables:
   • The DISCOVER_STORAGE_TABLE_COLUMN_SEGMENTS DMV used in the previous chapter's Importing and visualizing dynamic management view (DMV) data of SSAS and Power BI data models recipe will provide this detail.
2. As per the Choosing columns and column names recipe of Chapter 2, Accessing and Retrieving Data, identify expensive columns that may not be needed in the dataset or which can be rounded to lower precision, split as separate columns, or expressed via simple measures.

For import mode models, an expensive column is one with many unique values (high cardinality), such as the Order Number columns used as ...