Author: K Z

Redis PFMERGE command is used to merge multiple HyperLogLog values into a unique value that will approximate the cardinality of the union of the observed sets of the source HyperLogLog structures. Return…

Redis PFCOUNT command is used to get the approximated cardinality computed by the HyperLogLog data structure stored at the specified variable. If the key does not exist, then it returns 0. Return…

Redis PFADD command adds all the element arguments to the HyperLogLog data structure stored at the key name specified as first argument. Return Value Integer reply, 1 or 0. Syntax Following is…

Redis HyperLogLog is an algorithm that uses randomization in order to provide an approximation of the number of unique elements in a set using just a constant, and small amount…

Redis ZSCAN command iterates the elements of Sorted Set types and their associated scores. Return Value Array reply. Syntax Following is the basic syntax of Redis ZSCAN command. redis 127.0.0.1:6379> ZSCAN key cursor [MATCH…

Redis ZUNIONSTORE command calculates the union of numkeys sorted sets given by the specified keys, and stores the result in the destination. It is mandatory to provide the number of input keys…

Redis ZSCORE command returns the score of the member in the sorted set at the key. If the member does not exist in the sorted set, or the key does not exist,…

Redis ZREVRANK command returns the rank of the member in the sorted set stored at the key, with the scores ordered from high to low. The rank (or index) is 0-based, which…

Redis ZREVRANGEBYSCORE command returns all the elements in the sorted set at the key with a score between max and min (including elements with score equal to max or min). In contrary…

Redis ZREVRANGE command returns the specified range of elements in the sorted set stored at the key. The elements are considered to be ordered from the highest to the lowest score. Descending…