redis-core

SKILL.md

Redis Core

Foundational guidance for modeling data in Redis. Covers data-type selection and key-name conventions — the two decisions that most directly drive memory, performance, and maintainability.

When to apply

Caching objects, sessions, or per-user state.

Counters, leaderboards, recent-items lists, unique-membership sets.

Reviewing or refactoring Redis key names.

Deciding between a Redis Hash and a JSON document for an entity.

1. Choose the right data structure

Pick the type that matches the access pattern, not just the shape of the data.

Use case
Recommended type
Why

Simple values, counters
String
Atomic INCR/DECR, SET/GET

Object with independently updated fields
Hash
Per-field reads/writes, no whole-object rewrite

Queue, recent-N items
List
O(1) push/pop at ends

Unique items, membership checks
Set
O(1) SADD/SISMEMBER/SCARD

Rankings, score-based ranges
Sorted Set
Score-ordered; ZADD/ZRANGE/ZRANK

Nested / hierarchical data
JSON
Path-level updates, nested arrays, RQE indexing

Event log, fan-out messaging
Stream
Persistent, consumer groups

Vector similarity
Vector Set
Native vector storage with HNSW

Common anti-pattern: stuffing a flat object into a serialized string. Updating one field means fetch + parse + mutate + rewrite. Use a Hash instead.

See references/choose-data-structure.md for full rationale and Python/Java examples.

2. Use consistent key names

Use colon-separated segments with a stable hierarchy:

{entity}:{id}:{attribute}
user:1001:profile
user:1001:settings
order:2024:items
session:abc123
article:987:likes
game:space-invaders:leaderboard

Rules of thumb:

Lowercase, colon-separated. No spaces, no mixed casing (User_1001_Profile is bad).

Keep keys short but readable — keys live in memory and appear in every command.

Don't use full URLs or long strings as keys. Extract a short identifier, or use a hash digest of the URL.

Prefix for multi-tenancy (tenant:42:user:7:cart) so scans and ACLs can target a tenant cleanly.

Be consistent. Pick one convention per service and apply it across all keys.

See references/key-naming.md for cleanup examples and edge cases.

References

Redis: Choosing the right data type

Redis: Keys

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