Restrictions on nested-table-expressions for error tolerance

A query or view is read-only when you define the query or view with an expression that contains the RETURN DATA UNTIL clause. Cursors that are declared in expressions with the RETURN DATA UNTIL clause are read-only. Errors are returned for each of those situations.

If a connection failure occurs, an initial connection failure is tolerated. An initial connection failure occurs during a connection attempt to a data source. An attempt to connect to a data source occurs the first time a query is issued to a data source within a connection or after a connection loss. A connection loss or failure that is not an initial connection failure is not tolerated.