Hashes

Field/value maps

A hash holds many fields—handy for a user profile or session blob without nested JSON parsing.

HSET user:1 name "Ada" email "[email protected]"
HGET user:1 name
HGETALL user:1

Partial updates

Change one field without rewriting the whole object.

HSET user:1 email "[email protected]"
HDEL user:1 temp

Increment fields

Numeric hash fields support HINCRBY.

HINCRBY user:1 login_count 1

Hash vs JSON string

Hashes make field updates cheap. A single JSON string is simpler for opaque blobs you always read whole.