Validate the standby with the broker before switchover/failover (VALIDATE DATABASE)

Command

VALIDATE DATABASE '<standby_db_unique_name>';
VALIDATE DATABASE VERBOSE '<standby_db_unique_name>';
# spfile parameter differences between the two sides:
VALIDATE DATABASE '<standby_db_unique_name>' SPFILE;
# Network and static listener registrations (18c+):
VALIDATE NETWORK CONFIGURATION FOR ALL;
VALIDATE STATIC CONNECT IDENTIFIER FOR ALL;

What it does

Checks whether the standby is ready for a role change ("Ready for Switchover / Failover: Yes"), the number/size of standby redo logs, flashback and apply state, spfile differences, and the static services the broker needs to restart instances.

When to use it

As a mandatory step before every planned switchover; after building a new standby and after network/listener changes.

Caution

Read-only. If you see "Ready for Switchover: No" or a standby redo log warning, do not proceed with the switchover. A static connect identifier error means the broker cannot start the instance during a switchover, which forces manual intervention.