Courses / Power Query (Get & Transform)
43. Step ordering and type changes in Power Query M
How the order of applied steps and type changes affects refresh speed and memory usage.
Power Query M
Step ordering and type changes in Power Query M
The order you apply filters, column removals, and type conversions in a Power Query determines how much data Power Query loads into memory and how fast a refresh runs.
"I made my query correct, but the refresh is painfully slow and sometimes runs out of memory."
Power Query evaluates steps in sequence, and some operations (especially explicit type changes and certain transformations) force the engine to materialize data; placing costly operations before reduction steps (filters, column removal, grouping) increases memory use and slows refresh.
"I made my query correct, but the refresh is painfully slow and sometimes runs out of memory."
Power Query evaluates steps in sequence, and some operations (especially explicit type changes and certain transformations) force the engine to materialize data; placing costly operations before reduction steps (filters, column removal, grouping) increases memory use and slows refresh.