You administer a RAC database that currently runs on a four-node cluster but which has three instances.
Which two statements are always true about redo logs for this RAC database? (Choose two.)
A.
A thread of redo must be created before starting a fourth instance if a thread is not already available.
B.
A thread of redo must contain at least two log groups before it can be enabled.
C.
A redo log group added using ALTER DATABASE ADD LOGFILE without the INSTANCE clause is added to
each instance.
D.
All the instances must have the same number of redo log groups and each group must have the same
number of redo log members.
E.
A thread of redo is automatically dropped when as instance is removed from a RAC database by using
SRVCTL.
A,B