Redis ttl payload memory size

Question

I am wondering how much memory space does enabling TTL for a particular key will use. To be more precise, if I enable TTL for a key, how much memory does this settings will consume and how to check the memory consumption by setting such TTL?

Answer 1

TTL doesn't consume any extra space. The internal memory allocation for it is performed when creating a key, whether you use it or not.

PS IIRC, the TTL is a 64-bit variable, so it "costs" 8 bytes.