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Diffstat (limited to 'iredis/data/commands/zintercard.md')
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diff --git a/iredis/data/commands/zintercard.md b/iredis/data/commands/zintercard.md new file mode 100644 index 0000000..613849f --- /dev/null +++ b/iredis/data/commands/zintercard.md @@ -0,0 +1,25 @@ +This command is similar to `ZINTER`, but instead of returning the result set, it returns just the cardinality of the result. + +Keys that do not exist are considered to be empty sets. +With one of the keys being an empty set, the resulting set is also empty (since set intersection with an empty set always results in an empty set). + +By default, the command calculates the cardinality of the intersection of all given sets. +When provided with the optional `LIMIT` argument (which defaults to 0 and means unlimited), if the intersection cardinality reaches limit partway through the computation, the algorithm will exit and yield limit as the cardinality. +Such implementation ensures a significant speedup for queries where the limit is lower than the actual intersection cardinality. + +@return + +@integer-reply: the number of elements in the resulting intersection. + +@examples + +```cli +ZADD zset1 1 "one" +ZADD zset1 2 "two" +ZADD zset2 1 "one" +ZADD zset2 2 "two" +ZADD zset2 3 "three" +ZINTER 2 zset1 zset2 +ZINTERCARD 2 zset1 zset2 +ZINTERCARD 2 zset1 zset2 LIMIT 1 +``` |