ISOLATION LEVEL

Controls the locking and row versioning behavior of T-SQL statements issued by a connection to SQL Server

Isolation level	Transact SQL access	File system access
Read uncommitted	SQL Server 2016	Unsupported
Read committed	SQL Server 2016	SQL Server 2016
Repeatable read	SQL Server 2016	Unsupported
Serializable	SQL Server 2016	Unsupported

Snapshot 

SET TRANSACTION ISOLATION LEVEL
    { READ UNCOMMITTED
    | READ COMMITTED
    | REPEATABLE READ
    | SNAPSHOT
    | SERIALIZABLE
    }