Oracle Database / Data Guard & High Availability
Confirm database role before diagnosing a Data Guard issue
A connection may reach a primary, standby or a database in an unexpected open mode. Establish the current role before planning any action.
Environment and inputs: Oracle Database 19c baseline · SQL*Plus-compatible SQL unless RMAN, DGMGRL, ADRCI or a host shell is specified. Check release, patch level, edition and container first.
Start with this diagnostic
Use the stated SQL, RMAN, DGMGRL or host shell and replace sample names with approved targets. DBA and V$ views need authorized catalog access in the correct container. Do not grant broad privileges for an example.
SELECT name, db_unique_name, database_role, open_mode, switchover_status FROM v$database;Read the result
The row describes this database's present role and state. SWITCHOVER_STATUS is one readiness signal and is not a complete transition checklist.
Resolve and verify
Compare the result with the intended topology and application service placement. Route any mismatch through the Data Guard change procedure.
Operational precautions
Do not activate a standby or perform a role transition based on a single state field.