FLASHBACK and BLOCK CHANGE TRACKING
[et_pb_section fb_built=”1″ admin_label=”section” _builder_version=”4.16″ global_colors_info=”{}”][et_pb_row admin_label=”row” _builder_version=”4.16″ background_size=”initial” background_position=”top_left” background_repeat=”repeat” global_colors_info=”{}”][et_pb_column type=”4_4″ _builder_version=”4.16″ custom_padding=”|||” global_colors_info=”{}” custom_padding__hover=”|||”][et_pb_text admin_label=”Text” _builder_version=”4.16″ background_size=”initial” background_position=”top_left” background_repeat=”repeat” global_colors_info=”{}”] Enabling Flashback Database and Block Change Tracking in Oracle database: A Step-by-Step Guide Introduction Oracle provides powerful features like Flashback Database and Block Change Tracking, offering database administrators a robust set of tools for data recovery and performance optimization. In this guide, we’ll walk you through the process of enabling these features step by step. Enabling Flashback Database Step 1: Configure Fast Recovery Area Before enabling Flashback Database, ensure your Oracle database is running in ARCHIVELOG mode and has a configured fast recovery area. — Ensure the database is running in ARCHIVELOG mode firstSQL> ALTER DATABASE ARCHIVELOG; — Set the location and size for the fast recovery areaSQL> ALTER SYSTEM SET DB_RECOVERY_FILE_DEST = ‘/path/to/fast_recovery_area’ SCOPE=BOTH; — Set the maximum size for the fast recovery areaSQL> ALTER SYSTEM SET DB_RECOVERY_FILE_DEST_SIZE = 10G SCOPE=BOTH; Make sure to replace ‘/path/to/fast_recovery_area’ with the actual path where you want to store the fast recovery area files. The size specified in the example is 10GB; you can adjust it based on your storage requirements. Step 2: Check Flashback Database Status Determine if Flashback Database is already enabled by executing the following SQL command: SQL> SELECT FLASHBACK_ON FROM V$DATABASE; Step 3: Set Flashback Window (Optional) Optionally, set the length of the flashback window in minutes by adjusting the DB_FLASHBACK_RETENTION_TARGET parameter. For instance, to specify a 15-day window: SQL> ALTER SYSTEM SET DB_FLASHBACK_RETENTION_TARGET=21600 scope=both; Step 4: Enable Flashback Database Enable Flashback Database for the entire database with the following SQL command: SQL> ALTER DATABASE FLASHBACK ON; Step 5: Enable Row Movement for the Table (OPTIONAL) For Flashback Database to work effectively, enable row movement for the relevant tables SQL> ALTER TABLE testing_tbl ENABLE ROW MOVEMENT; NOTE: Step-5 is not mandatory for enabling Flashback Database itself. It is an optional step that may be necessary in certain situations. Enabling row movement allows rows in a table to be moved, which can be useful when performing certain operations with Flashback Database. For example, if you want to perform a Flashback Query on a table and the table has a foreign key relationship with another table, enabling row movement might be required. If your database doesn’t involve operations or features that specifically require row movement, you can choose to skip this step. It is recommended to evaluate your database schema and requirements to determine whether enabling row movement is necessary for your use case. Step 6: Increase UNDO Retention Increase UNDO retention to cover the desired flashback window. The value is defined in seconds. For example, to set it to 15 days: SQL> ALTER SYSTEM SET UNDO_RETENTION = 1296000 scope=both; Enable Block Change Tracking Step 1: Create Directory Create a directory where the block change tracking file will be stored: oracle@OLPODA:/home/oracle> mkdir –p /u01/block_change_tracking_file/ Step 2: Enable Block Change Tracking Connect to the database and execute the following SQL commands: SQL> ALTER DATABASE ENABLE BLOCK CHANGE TRACKING;SQL> ALTER DATABASE ENABLE BLOCK CHANGE TRACKING USING FILE ‘/u01/block_change_tracking_file/rman_change_track.f’; Conclusion This completes the process of enabling Flashback Database and Block Change Tracking in your Oracle database. These features enhance data protection and performance tuning capabilities. [/et_pb_text][/et_pb_column][/et_pb_row][/et_pb_section]