Question

You are building a Dataflow Gen2 that ingests a 200-million-row transaction table from an on-premises SQL Server into a Fabric Lakehouse. The downstream report only needs transactions from the last 90 days. You want to minimize the volume of data transferred from the source system during refresh. In Power Query, which approach ensures the row filter is pushed to the source rather than applied after all data is loaded?

Accepted Answer

Apply a date filter step early in the query so that query folding pushes the WHERE clause to SQL Server

Answer

Load all rows into the Lakehouse first, then create a downstream view that filters to the last 90 days

Answer

Add a Table.Buffer step before the filter to cache the rows and speed up filtering

Answer

Use the Keep Bottom Rows transformation to retain only the most recent records