Question

You are optimizing a DAX query that produces a table of product categories with total sales. A colleague wrote it using SUMMARIZE with the aggregation expression placed directly inside the SUMMARIZE function, and profiling shows slow performance and high CallbackDataID activity in the storage engine. You want to rewrite the query so that the grouping is done efficiently and the aggregation runs in a proper row context without the performance issues of computing extended columns inside SUMMARIZE. Which approach should you use?

Accepted Answer

Use ADDCOLUMNS over a SUMMARIZE that only lists the group-by column, placing the aggregation in ADDCOLUMNS

Answer

Use SUMMARIZECOLUMNS with the group-by column and the sales measure as arguments

Answer

Keep SUMMARIZE but wrap the aggregation expression in CALCULATE to force context transition

Answer

Use GROUPBY with CURRENTGROUP inside a SUMX to aggregate the sales column