Redis ordered set (sorted set)

Redis ordered set and also set the same collection type string elements, and does not allow duplicate members.

The difference is that are associated with each type of element of a double score. It is through redis scores for small to large order of collection members.

Members of the ordered set is unique, but the score (score) it can be repeated.

Set by the hash table to achieve, so add, delete, find the complexity is O (1). Set the maximum number of members ^232--1 (4294967295 Each set can store more than 40 million members).

Examples

redis 127.0.0.1:6379> ZADD w3bigkey 1 redis
(integer) 1
redis 127.0.0.1:6379> ZADD w3bigkey 2 mongodb
(integer) 1
redis 127.0.0.1:6379> ZADD w3bigkey 3 mysql
(integer) 1
redis 127.0.0.1:6379> ZADD w3bigkey 3 mysql
(integer) 0
redis 127.0.0.1:6379> ZADD w3bigkey 4 mysql
(integer) 0
redis 127.0.0.1:6379> ZRANGE w3bigkey 0 10 WITHSCORES

1) "redis"
2) "1"
3) "mongodb"
4) "2"
5) "mysql"
6) "4"

In the example above, weZADD by adding commands to the ordered set redis of the three values and the associated scores.

Redis command ordered set

The following table lists the basic commands redis ordered sets: