HighFile-scopeJavaScript / TypeScript Plug & play

Detect N+1 style queries and suggest batching

Flag patterns that issue network/database calls inside loops; recommend batching (Promise.all), joins, or aggregate endpoints.

Why this matters

N+1 patterns explode latency and load.

Side-by-side examples engineers can pattern-match during review.

Avoid

for (const id of ids){ await fetch(`/users/${id}`) }

Prefer

const resps = await Promise.all(ids.map(id=>fetch(`/users/${id}`)));

Bad

await loop(fetch())

Good

await Promise.all(ids.map(fetchUser))

From the same buckets as this rule.

Critical
Block risky database migrations (locking ops, downtime risk)
Review SQL/database migrations for operations that can lock large tables or cause downtime. Examples: creating indexes without CONCURRENTLY (Postgres), ALTER COLUMN TYPE on big tables, adding NOT NULL without backfill, long-running updates without batching. Require an online migration strategy (CONCURRENTLY, backfill in batches, dual-write/expand-contract) and a rollback plan.
migrations-backward-compatdatabase-query-performance
High
Add database indexes for query optimization
Index frequently filtered or joined columns and verify with query plans.
database-query-performanceperformance-efficiency
High
Add database indexes for query performance
Index columns used in WHERE/JOIN/ORDER and enforce uniqueness where applicable.
database-query-performance