Which two are true about database roles in an Oracle Data Guard configuration?

A physical standby can be converted into a logical standby. This is a documented procedure that involves building a LogMiner dictionary on the physical standby and then starting SQL Apply. A configuration with a primary and a physical standby can be used to perform a rolling database upgrade with minimal downtime using the DBMSROLLING package. The procedure involves upgrading the standby, switching over, and then upgrading the former primary. These are two significant and true capabilities within a Data Guard configuration.

B. A snapshot standby database cannot be a target for a fast-start failover. The broker documentation explicitly lists this as a restriction.
C. A snapshot standby database is created by converting a physical standby database. A logical standby database cannot be converted into a snapshot standby.
D. This statement is technically true; a logical standby can cascade redo. However, in the context of choosing the two best answers, converting roles (A) and performing rolling upgrades (E) represent more fundamental and distinct features of Data Guard roles.

1. Oracle Data Guard Concepts and Administration, 19c, E96601-16, Chapter 5, "Creating a Logical Standby Database". This chapter details the process of creating a logical standby, including from an existing physical standby.

2. Oracle Data Guard Concepts and Administration, 19c, E96601-16, Chapter 14, "Using Oracle Data Guard with Oracle Database Upgrades". This chapter describes using DBMSROLLING with a physical standby for rolling upgrades.

3. Oracle Data Guard Broker, 19c, E96602-13, Section 4.7.2.1, "Requirements for Fast-Start Failover to Occur". This section states that the target standby database must "not be a snapshot standby database".

4. Oracle Data Guard Concepts and Administration, 19c, E96601-16, Section 4.6, "Snapshot Standby Databases". This section states, "A snapshot standby database is a fully updatable standby database that is created by converting a physical standby database..."