Acct-Unique-Session-Id Uniqueness

[Ali Arslan]

Hello,

I am using freeradius 3.0.20 on ubuntu 20.04 with backend mssql.
I have problem with the uniqueness of AcctUniqueId ( Acct-Unique-Session-Id ), but they are not unique across radacct table.
Because there may be multiple records with the same AcctUniqueId value an interim update updates all records with the same AcctUniqueId  value even for different users, which is a problem for usage calculation, and for some other custom calculations, 

I want to create AcctUniqueId in database as a "uniqueidentifier" so it is unique in database which can be retrieved as a string to be used as "Acct-Unique-Session-Id" in radius when inserting a new record. If it is possible to generate a guid by unlang and use it then it would be better.
I think raddb/policy.d/accounting file is where this value is created,
Any suggestion about making Acct-Unique-Session-Id as unique in radacct table will be greatly appreciated.