SQL Query Timeout
The query exceeds an execution or application timeout.
LIKELY CAUSE
Why it happens
Reduce source rows, inspect joins, indexes and execution plan, then split expensive logic if needed.
SAFE FIX
What to do
Start with the largest scans and join cardinalities.
Debug in this order
- Reproduce the problem on the smallest sample that still fails.
- Inspect the exact keys, types, ranges or markup involved instead of only the displayed value.
- Fix the root cause, then rerun the original case and one known-good case.
- Document the rule if the same problem can return in recurring work.
Do not hide an unexplained data error with a cosmetic workaround. Make the input and matching logic predictable first.