Where do I find the source for the ldap schema in Samba4

[Krishna Ganugapati]

Hello, could someone point me to where the schema is stored in Samba4. Specific questions
a) is it a readonly schema
b) does the Samba4 ldap schema architecture similar to openldap's .schema files
c)  Is the schema stored within the directory in a separate naming context?
d) Is the Samba4 schema dynamically updateable?

Thanks

Krishna