Glossary

Redis · Reference cheat sheet

📋 Overview

Alphabetical glossary of Redis data structures, durability, and client terms.

Term	Definition
AOF	Append-only file persistence log of write operations.
Eviction	Removing keys under `maxmemory` per policy.
Hash	Field-value map stored at a single key.
Keyspace	The set of keys in a selected logical database.
List	Ordered sequence supporting push/pop at ends.
Pub/Sub	Fire-and-forget channel messaging.
RDB	Snapshot persistence format.
Replica	Read copy of a primary for HA/scale-out reads.
Set	Unordered collection of unique members.
Sorted set	Unique members ordered by score.
Stream	Append-only log with consumer groups.
TTL	Time-to-live before a key expires.
`SCAN`	Cursor-based incremental iteration.

Type check:

TYPE session:abc
TTL session:abc

Logical DB:

SELECT 0

“Persistent Redis” still needs backup/HA design — persistence ≠ full DR plan.
Mixing cache and primary data on one instance without key discipline causes pain.