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Cluster cluster addslots(集群 槽位) cluster count failure reports(集群计数失败报告) cluster countkeysinslot cluster delslots cluster failover cluster forget cluster getkeysinslot cluster info cluster keyslot(集群键槽) cluster meet cluster nodes(集群节点) cluster replicate(集群复制) cluster reset(集群重置) cluster saveconfig cluster set config epoch cluster setslot cluster slaves cluster slots readonly readwrite Connection auth echo ping quit select swapdb Geo geoadd geodist geohash geopos georadius georadiusbymember Hashes hdel hexists hget hgetall hincrby hincrbyfloat hkeys hlen hmget hmset hscan hset hsetnx hstrlen hvals HyperLogLog pfadd pfcount pfmerge Keys del dump exists expire expireat keys migrate move object persist pexpire pexpireat pttl randomkey rename renamenx restore scan sort touch ttl type unlink wait Lists blpop brpop brpoplpush lindex linsert llen lpop lpush lpushx lrange lrem lset ltrim rpop rpoplpush rpush rpushx Pub/Sub psubscribe publish pubsub punsubscribe subscribe unsubscribe Scripting eval evalsha script debug script exists script flush script kill script load Server bgrewriteaof bgsave client getname client kill client list client pause client reply client setname command command count command getkeys command info config get config resetstat config rewrite config set dbsize debug object debug segfault flushall flushdb info lastsave monitor role save shutdown slaveof slowlog time Sets sadd scard sdiff sdiffstore sinter sinterstore sismember smembers smove spop srandmember srem sscan sunion sunionstore Sorted Sets zadd zcard zcount zincrby zinterstore zlexcount zrange zrangebylex zrangebyscore zrank zrem zremrangebylex zremrangebyrank zremrangebyscore zrevrange zrevrangebylex zrevrangebyscore zrevrank zscan zscore zunionstore Strings append bitcount bitfield bitop bitpos decr decrby get getbit getrange getset incr incrby incrbyfloat mget mset msetnx psetex set setbit setex setnx setrange strlen Transactions discard exec multi unwatch watch
characters

PFADD key element [element ...]

自2.8.9起可用。

时间复杂度: O(1)添加每个元素。

将所有元素参数添加到以指定为第一个参数的变量名称存储的HyperLogLog数据结构中。

作为该命令的副作用,HyperLogLog 内部件可能会更新以反映迄今为止添加的唯一项目数量(集合的基数)的不同估计值。

如果 HyperLogLog 估计的近似基数在执行命令后发生改变,则PFADD 返回1,否则返回0。如果指定的键不存在,该命令将自动创建一个空的 HyperLogLog 结构(即,具有指定长度和给定编码的Redis字符串)。

要调用没有元素的命令,但只是变量名是有效的,如果变量已经存在,这将导致不执行任何操作,或者如果该键不存在,则只是创建数据结构(在后一种情况下返回1) 。

有关 HyperLogLog 数据结构的介绍,请查看 PFCOUNT 命令页面。

返回值

整数回复,具体为:

  • 1如果至少有1个HyperLogLog内部寄存器被更改。否则为0。

例子

redis>  PFADD hll a b c d e f g (integer) 1 

redis>  PFCOUNT hll (integer) 7

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