Question about "max-cache-size" value

[Techs-yama]

Hello,

I have a question about the "max-cache-size" parameter for named.conf.

I'm thinking about this parameter value,
How does everyone tuning this value?
Would you let us know if you have any recommendations?

How is memory used for "named".
Such as to how allocated process memory, heap, cache-memory-space and more.
Should not be used the value of "unlimited"?

Thank you.