Hi,

The Repeatable Read isolation level allows a transaction to acquire read locks on all rows of data it returns to an application, and write locks on all rows of data it inserts, updates, or deletes.All data records read by a SELECT statement cannot be changed; however, if the SELECT statement contains any ranged WHERE clauses, phantom reads can occur. When it's used, the dirty reads and nonrepeatable reads cannot occur. It means that locks will be placed on all data that is used in a query, and another transactions cannot update the data.

Thanks,