Power Query converting your steps into a query in the source's own language, so the database or service does the heavy lifting rather than the mashup engine. Folding indicators, and the query plan, let you check which steps get pushed down.
Read more: Microsoft Learn
In the Ultra Transcenders books
Each book explains Query folding in context, with comparison tables and the common traps.
Terms in this definition
- Schema
The middle part of a Unity Catalog name (
catalog.schema.table), grouping tables, views, volumes, functions and models inside a catalog. A grant on it covers everything in it now and later, and nothing inside can be reached withoutUSE SCHEMA. - Query plan
Shows, in Power Query Online, how a step will be evaluated after optimisation: which parts are pushed down to the source (Value.NativeQuery, for example) and which are processed by the Power Query engine itself.
- Get
Key Vault permission on secrets that allows a single secret to be read; App Service Key Vault references need nothing beyond it.
Related terms
- View Native Query
A Power Query command, also labelled View data source query, that displays what a step sends to the source. If it is greyed out on a step where the source normally supports it, query folding has stopped at that step.