The scenario
Replace a per-row lookup with one batched load without changing the report output.
A failure to reason about
A report is correct for three orders but sends a separate related-data query for every row as the report grows.
Illustrative context for the topic. The exercise’s full requirements arrive in the workspace.
Questions to bring to your review
- Which caller makes the reported behavior visible?
- What focused regression would distinguish the current behavior from the requirement?
- What existing behavior must remain intact after the change?
Skills you will practice
- Query batching
- Data access
- Performance
Read the existing code, reproduce the reported behavior, review proposed changes, and verify your final implementation. You can use AI assistance while staying responsible for the result.
Prepare with a worked example
- How to review AI-generated code
A worked review of a cache patch: establish the contract, find a counterexample, verify the fix, and explain the evidence.
See how nrml evaluates an attempt, including the limits of automated evidence.