19c New Features Data Guard

Introduction

Some real good progress in this area with some great new enhancements. They are not ground breaking in functionality, but if you manage DG environments, especially in the support environment, they will rock your world.

Fast Start Failover (FSF)

There is no longer any need to disable FSF when you want to change the target standby database. You can just go right in there and update the target dynamically.

The command SET FAST_START FAILOVER TARGET can be used to dynamically make the change.

Database Parameter and the Data Guard Broker

Possibly one of my favorite enhancements in the Data Guard arena. Previous releases it was easy to get inconsistencies between the Database Data Guard parameters and the data Guard Broker settings. Not anymore. If you make a change in the Data Guard Broker (DGMGRL), they are automatically issued on the database. Conversely, if you make them 9in SQLPLUS, they are automatically issued against the data guard broker. For the data guard broker changes you need to use the new command EDIT DATABASE … SET PARAMETER

Restore Points

Another great enhancement, up there with the Broker Parameter change. Its such a simple, but elegant change. Restore points are now automatically propagated to the standby database making them available after a switchover.

Flashback of Standby when the Primary is Flashed Back

When using flashback database in a Data Guard configuration, the standby database is automatically flashed back too if in mount mode. If you do not want the standby database to be flashed back automatically, then keep the standby database open or stop the managed recovery process

Multi Instance Redo Apply and In-Memory Column Store

In previous releases these two features were incompatible. From 19c onward, they can both be enabled.

Other features

There are quite a few more enhancements/features in this area which people should checkout if they have these set-ups. I have listed a few below

  • Observe only Mode for Fast-Start Failover
  • Active Data Guard DML Redirection
  • New Parameters to Tune Automatic Outage Resolution with Oracle Data Guard
  • Support for Multi-Shard Query Coordinators on Shard Catalog Standby Databases

Published 10th May 2023

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