Isolate Analytics Workloads from Production Databases

One system began showing intermittent failures in invoicing, financial operations, and background jobs. The cause was not in the application path itself, but in expensive analytical queries that Power BI was sending to the production database.

A read-only account prevents data changes, but it does not prevent full-table scans or heavy use of CPU, memory, and I/O. Long-running queries can also affect concurrency depending on the engine, isolation level, and execution plan.

The solution was to create a read replica for reporting and connect analytical tools to it, leaving the primary database to serve the application. When unexplained latency or locking appears, inspect every database client and its query plans—not only application code. Reporting workloads also need timeouts, resource limits, and their own monitoring.