Avoid forcing this pattern when:
- Array changes frequently: Prefix sum requires rebuild after modifications. Use segment tree for dynamic arrays.
- Single query only: For one range query, direct summation is simpler than building prefix array.
- Non-sum operations: Prefix sums don't generalize to all operations.
Use segment trees for min/max queries. Remember: forcing a pattern where it doesn't fit leads to overcomplicated solutions. If you find yourself fighting the approach, step back and reconsider whether another technique works better.