What is maxsigcachesize?

Question

-maxsigcachesize= Limit sum of signature cache and script execution cache sizes to

What is this? What is a sigcache? What happens if it is set low and Can it have a bad effect?

Answer 1

Bitcoin Core caches the outcome of script and signature validations, so that when they are reoccur, they don't need to be repeated.

A common case for this reoccurrence is the fact that typical transactions get processed twice: once when received as an unconfirmed transaction individually, and once when it is mined in a block and that block is processed. The script validation cache avoids the need to run the script again a second time, if it happens within a sufficiently short period of time.

You can safely ignore this option; its default value should be more than adequate.