Redis Sets are an unordered collection of unique strings. Unique means sets does not allow repetition of data in a key.

In Redis set add, remove, and test for the existence of members in O(1) (constant time regardless of the number of elements contained inside the Set). The maximum length of a list is 2³² – 1 elements (4294967295, more than 4 billion of elements per set).

Example

redis 127.0.0.1:6379> SADD tutorials redis 
(integer) 1 
redis 127.0.0.1:6379> SADD tutorials mongodb 
(integer) 1 
redis 127.0.0.1:6379> SADD tutorials mysql 
(integer) 1 
redis 127.0.0.1:6379> SADD tutorials mysql 
(integer) 0 
redis 127.0.0.1:6379> SMEMBERS tutorials  
1) "mysql" 
2) "mongodb" 
3) "redis"

In the above example, three values are inserted in Redis set named ‘tutorials’ by the command SADD.

Redis Sets Commands

Following table lists some basic commands related to sets.