The Data Guard Broker PREPARE DATABASE FOR DATA GUARD command configures a database to be used as a Primary Database in a Data Guard Broker configuration.
It enables and sets a number of database parameters like LOG_BUFFER, DG_BROKER_START, STANDBY_FILE_MANAGEMENT, DB_BLOCK_CHECKSUM etc.
It also enables FLASHBACK and ARCHIVELOG for the database and creates the Standby Redo Log files if they do not exist.
In addition, it enables FORCE LOGGING for the database and configures the RMAN property for archivelog deletion to SHIPPED TO ALL STANDBY.
[oracle@db21c ~]$ dgmgrl DGMGRL for Linux: Release 21.0.0.0.0 - Production on Wed Jan 6 01:49:17 2021 Version 21.1.0.0.0 Copyright (c) 1982, 2020, Oracle and/or its affiliates. All rights reserved. Welcome to DGMGRL, type "help" for information. DGMGRL> connect sys/### Connected to "cdb2" Connected as SYSDBA. DGMGRL>PREPARE DATABASE FOR DATA GUARD WITH DB_UNIQUE_NAME IS cdb2 DB_RECOVERY_FILE_DEST IS "+RECO" DB_RECOVERY_FILE_DEST_SIZE is "20G"; Preparing database "cdb2" for Data Guard. Initialization parameter LOG_BUFFER set to 268435456. Primary database must be restarted after setting static initialization parameters. Primary database must be restarted to enable archivelog mode. Shutting down database "cdb2". Database closed. Database dismounted. ORACLE instance shut down. Starting database "cdb2" to mounted mode. ORACLE instance started. Database mounted. Initialization parameter DB_FLASHBACK_RETENTION_TARGET set to 120. Initialization parameter PARALLEL_THREADS_PER_CPU set to 1. RMAN configuration archivelog deletion policy set to SHIPPED TO ALL STANDBY. Initialization parameter DB_RECOVERY_FILE_DEST_SIZE set to '20G'. Initialization parameter DB_RECOVERY_FILE_DEST set to '+RECO'. LOG_ARCHIVE_DEST_n initialization parameter already set for local archival. Initialization parameter LOG_ARCHIVE_DEST_2 set to 'location=use_db_recovery_file_dest valid_for=(all_logfiles, all_roles)'. Initialization parameter LOG_ARCHIVE_DEST_STATE_2 set to 'Enable'. Adding standby log group size 1073741824 and assigning it to thread 1. Adding standby log group size 1073741824 and assigning it to thread 1. Adding standby log group size 1073741824 and assigning it to thread 1. Initialization parameter STANDBY_FILE_MANAGEMENT set to 'AUTO'. Initialization parameter DG_BROKER_START set to TRUE. Database set to FORCE LOGGING. Database set to ARCHIVELOG. Database set to FLASHBACK ON. Database opened.
