MEMORY USAGE key [SAMPLES count]

    Time complexity: O(N) where N is the number of samples.

    The reported usage is the total of memory allocations for data and administrative overheads that a key its value require.

    With Redis v4.0.1 64-bit and jemalloc, the empty string measures as follows:

    2. > MEMORY USAGE foo
    3. (integer) 54
    5. OK
    6. 127.0.0.1:6379> MEMORY USAGE cento

    *Return value

    : the memory usage in bytes