These are the changes in Oracle Data Guard Concepts and Administration for Changes in Oracle Database Release 18c, Version 18.1.

• The database buffer cache state is now maintained on an Oracle Active Data Guard standby during a role change. See Role Transitions Involving Physical Standby Databases.

• Global temporary tables can now be dynamically created on an Oracle Active Data Guard standby database. See Global Temporary Tables on Active Data Guard Instances.

• A new initialization parameter, ADG_ACCOUNT_INFO_TRACKING, extends control of user account security against login attacks across a production database and all Oracle Active Data Guard standby databases. See Oracle Database Reference.

• A new view V$DATAGUARD_PROCESS (which replaces V$MANAGED_STANDBY) provides information that can be queried to verify that redo is being transmitted from the primary database and applied to the standby database. See Creating a Physical Standby Task 7: Verify the Physical Standby Database Is Performing Properly.

• Metadata for private temporary tables (also known as local temporary tables) can be stored in memory. This allows private temporary tables to be enabled on read-only databases, hence allowing reporting applications to run on Oracle Active Data Guard standby databases. See Private Temporary Tables on Active Data Guard Instances.

• Database nologging has been extended with two new modes: Standby Nologging for Load Performance and Standby Nologging for Data Availability. These modes provide better support for use in an Oracle Active Data Guard environment without significantly increasing the amount of redo generated. See Enable an Appropriate Logging Mode.

• In-Memory column store is now supported with multi-instance redo apply in an Oracle Active Data Guard environment. See IM Column Store in an Active Data Guard Environment.

• A standby database can now be refreshed over the network using one RMAN command, RECOVER STANDBY DATABASE. See Rolling Forward a Standby With One Command.

• Enhancements have been made to Data Guard broker support for upgrades performed using the DBMS_ROLLING PL/SQL package. See Data Guard Broker Support for DBMS_ROLLING Upgrades.

• Block Change Tracking is now supported with multi-instance redo apply. See Setting Up Multi-Instance Redo Apply.