Forum Discussion
Unexpected multiple Athena query executions in Power BI
The unexpected Athena activity is likely driven by Power BI's metadata maintenance and its multi-query engine.
Why it’s happening
• The 6:00 AM Gap: This is usually Dashboard Tile Refreshes or Cache Updates. Even if a scheduled refresh is at 10:00 AM, pinned dashboard tiles or "Automatic Page Refresh" settings trigger independent queries to check for schema or data changes.
• Multiple 10:00 AM Scans: * Visual Parallelism: Power BI executes a separate query for every visual on a page. Five charts = five Athena scans.
• Privacy Levels: If Data Privacy levels are set to "Organizational" or "Private," the engine often runs redundant queries to prevent data leakage between sources.
Quick Fixes
• Consolidate Privacy Levels: Set all data sources to "Public" (if permitted) in the Power BI Service credentials settings to allow for better query folding.
• Check Dashboard Tiles: Disable or reduce the "Cache update frequency" in the dataset settings to stop pre-refresh queries.
• Enable Query Caching: If using Power BI Premium, turn on Query Caching to reuse Athena results for identical visuals.
• Partition Data: Ensure your S3 data is partitioned. This prevents Power BI’s "small" visual queries from triggering a "full" dataset scan.
What you are seeing is expected behavior. The scheduled refresh time in Power BI Service does not control when queries are sent to the data source. The Service runs automatic background operations such as schema validation, permission checks, and internal health checks, and these can trigger query executions hours before the configured refresh window. At refresh time, Power BI may execute multiple identical queries in parallel as part of internal validation processes, and there is no guarantee of query deduplication, so each execution can result in a full scan in Athena. Settings like disabling background data preview apply only to Power BI Desktop and do not affect Service behavior. There is no way to delay, throttle, or schedule query execution from Power BI itself, so any mitigation must be done on the Athena side, for example by enabling query result reuse, reducing scanned data through partitioning and column pruning, using CTAS tables or materialized views, or setting limits via workgroups. Opening a Microsoft support ticket can be useful if you need official confirmation, but in most cases support will confirm that this is by-design behavior rather than a bug.
If this post helps, then please consider Accepting it as the solution to help the other members find it more quickly
Super UserWhat you are seeing is expected behavior. The scheduled refresh time in Power BI Service does not control when queries are sent to the data source. The Service runs automatic background operations such as schema validation, permission checks, and internal health checks, and these can trigger query executions hours before the configured refresh window. At refresh time, Power BI may execute multiple identical queries in parallel as part of internal validation processes, and there is no guarantee of query deduplication, so each execution can result in a full scan in Athena. Settings like disabling background data preview apply only to Power BI Desktop and do not affect Service behavior. There is no way to delay, throttle, or schedule query execution from Power BI itself, so any mitigation must be done on the Athena side, for example by enabling query result reuse, reducing scanned data through partitioning and column pruning, using CTAS tables or materialized views, or setting limits via workgroups. Opening a Microsoft support ticket can be useful if you need official confirmation, but in most cases support will confirm that this is by-design behavior rather than a bug.
If this post helps, then please consider Accepting it as the solution to help the other members find it more quickly