link: Redis

Redis Data Structures

Redis supports a variety of data structures, each suited for different use cases. Here are the main data structures supported by Redis, along with examples for each.

Overview

Data Structures

• Strings: The simplest type of value, can hold any type of data including binary.
• Hashes: Ideal for storing objects and user profiles.
• Lists: Ordered collections of strings, useful for queues.
• Sets: Unordered collections of unique strings, ideal for relationships and tags.
• Sorted Sets: Like sets but with an associated score, useful for leaderboards.
• Bitmaps: For bit-level operations.
• HyperLogLogs: For approximate counting of unique items.

Details

Strings

Strings are the simplest Redis data type, holding any kind of data, such as text or binary.

Example:

SET key "value"
GET key

Hashes

Hashes are maps between string fields and string values, ideal for storing objects.

Example:

HSET user:1000 name "John" age 30
HGETALL user:1000

Lists

Lists are ordered collections of strings. They are useful for implementing queues.

Example:

LPUSH mylist "value1"
LPUSH mylist "value2"
LRANGE mylist 0 -1
 

Sets

Sets are unordered collections of unique strings, useful for managing relationships.

Example:

SADD myset "value1"
SADD myset "value2"
SMEMBERS myset

Sorted Sets

Sorted sets are similar to sets but with an associated score for each member, used for ranking.

Example:

ZADD leaderboard 100 "player1"
ZADD leaderboard 200 "player2"
ZRANGE leaderboard 0 -1 WITHSCORES
 

Bitmaps

Bitmaps are used for bit-level operations.

Example:

SETBIT mybitmap 10 1
GETBIT mybitmap 10

HyperLogLogs

HyperLogLogs are used for approximating the cardinality of a set, or counting unique items.

Example:

PFADD myhll "value1"
PFADD myhll "value2"
PFCOUNT myhll