ldap instead of /users file

Hello. I red that ldap can`t be used with eap-tls method to auth., but just what i wanna do is use LDAP instead of /raddb/users file . for example attribute VLAN ID etc. Is it possible? if yes, where i find some information about it? becouse everywhere is "howto authentication, authorization using LDAP" but i think its big different in radius configuration when i wanna use LDAP only instead of users file. THX for any information.