performance-analyzer

name: performance-analyzer description: Analyzes performance impact of query and code changes. Detects N+1 queries, missing indexes, sync-in-loops, unpaginated fetches, missing memoization, inefficient algorithms. Use for database query changes, loops, API changes, large file ops, or keywords fetch/query/loop/map/filter.

Performance Impact Analyzer

When to Trigger

• Database query changes
• Adding loops or iterations
• API route modifications
• Large file operations
• Keywords: "fetch", "query", "loop", "map", "filter"

What to Do

Step 1: Detect Anti-Patterns

Check for:

1. N+1 queries
2. Missing database indexes
3. Synchronous operations in loops
4. Large data fetches without pagination
5. Missing memoization (React)
6. Inefficient algorithms (O(n²) or worse)

Step 2: Estimate Impact

Report current vs after (e.g. query count, time). Explain why slower (e.g. N+1).

Step 3: Suggest Optimizations

• Replace N+1 with single query using include/select or JOINs.
• Add indexes for filtered/sorted columns.
• Add pagination (skip/take or cursor).
• Use useMemo/useCallback where appropriate.
• Prefer single aggregation over multiple sequential queries.

Show SLOW vs FAST code snippets. Ask: "Apply optimized version? (yes/no)".