One-time Oracle Database Setup for Oracle Goldengate 19c replication

1. Use the below Query to make sure that the database is in Archivelog mode and the force logging, flashback and Supplemental Logging is enabled:

SET LINES 200
COLUMN FORCE_LOGGING FORMAT A20
SELECT 
  name, 
  open_mode, 
  log_mode, 
  flashback_on, 
  force_logging, 
  supplemental_log_data_min 
FROM v$database;

-- If LOG_MODE is 'NOARCHIVELOG', enable Archivelog mode with the command (in MOUNT state): "ALTER DATABASE ARCHIVELOG;' 

-- if FLASHBACK_ON is 'NO', execute the command: SQL> alter database flashback on;
-- If FORCE_LOGGING is 'NO', execute the command: SQL> ALTER DATABASE FORCE LOGGING;
-- If supplemental_log_data_min is 'NO', execute the command: SQL> ALTER DATABASE ADD SUPPLEMENTAL LOG DATA;

All the above command should be run as privilege user (such as sys or system).
You should see the below output to confirm that the above setup is complete:

2. Set enable_goldengate_replication to TRUE (for 19c)

SQL> alter system set enable_goldengate_replication=true scope=both sid='*';

If you setting up Bi-Directional replication, the above configuration must be completed both for Source and Target database.