Fabric Performance Issue During GCP to Azure Migration: SELECT * from Views Hanging on F128 Capacity

Hi iamabhaykmr,

Thanks for reaching out to MS Fabric community forum.

Try below troubleshooting steps and let me know if this helps:

When facing this issue, first review overall Fabric capacity usage and check whether CU utilization is consistently high during the failures. Identify if heavy reports, refreshes, or other workloads are running in parallel on the same capacity. Capacity contention can significantly delay or stall query execution.

Try isolating workloads by pausing or rescheduling heavy reports during migration runs, or moving migration jobs to a separate capacity. Avoid using Select *  on complex views where possible—explicitly select required columns or materialize views into intermediate staging tables.

Validate the behavior by running the same queries during low‑usage periods and compare execution time and scanned data volume. If performance stabilizes under low load, this strongly indicates CU starvation rather than a functional issue.

Also review for long‑running transactions or write‑heavy operations that could cause blocking or deadlocks while queries are hanging. Scheduling migration activities during off‑peak hours can help reduce contention.

Thanks,

Prashanth