Oracle Database 23ai introduces a groundbreaking feature that simplifies the renaming of LOB segments. This enhancement offers database administrators a more efficient way to manage large data objects without resorting to complex workarounds.

LOBs play a critical role in storing massive data types such as images, documents, and videos. As databases grow and evolve, LOB segment names can become outdated or misaligned with business needs. Previously, renaming required duplicating LOBs, migrating data, and deleting old segments—an inefficient process. Before Oracle 23ai:

• Create a New LOB Column: A new LOB column had to be created in the table with the desired segment name.
• Migrate Data: Data from the old LOB segment had to be copied to the new LOB column.
• Drop Old LOB: Once the migration was completed, the old LOB column and segment were dropped.
• Rename Indirectly: This indirect process often required downtime and posed risks of data loss or corruption during migration.

Example (Pre-23ai Approach):

ALTER TABLE media ADD (file_data_temp BLOB);
UPDATE media SET file_data_temp = file_data;
ALTER TABLE media DROP COLUMN file_data;
ALTER TABLE media RENAME COLUMN file_data_temp TO file_data;

This method was cumbersome and inefficient for large databases … With Oracle 23ai, renaming LOB segments is now as simple as running a single command 🙂 🙂

Renaming LOB segments can be achieved with the following straightforward SQL command:

ALTER TABLE <table_name> MODIFY LOB (<lob_column>) (RENAME TO <new_segment_name>);

Suppose you manage a media table with a LOB column file_data, currently named FILE_DATA_LOB. To rename it to MEDIA_ARCHIVE_LOB: —> ALTER TABLE media MODIFY LOB (file_data) (RENAME TO MEDIA_ARCHIVE_LOB);

Practical Applications:

• Data Reorganization: Update segment names to align with evolving data categories.
• Simplifying Audits: Ensure LOB segment names clearly represent their purpose.
• Consistency Enforcement: Standardize naming conventions across different LOB segments.

Important Considerations

• Dependencies: Check for application-level dependencies that reference LOB segment names.
• User Privileges: Ensure you have the required ALTER permissions.
• Tablespace Integrity: Segment renaming does not affect the tablespace or physical location.

Automating LOB Segment Renaming

For larger environments, automating LOB segment renaming can save significant time. The following PL/SQL script demonstrates how to rename multiple segments programmatically:

BEGIN
  FOR r IN (SELECT table_name, column_name FROM user_lobs) LOOP
    EXECUTE IMMEDIATE 'ALTER TABLE ' || r.table_name || 
                     ' MODIFY LOB (' || r.column_name || 
                     ') (RENAME TO ' || r.column_name || '_UPDATEDLOB)';
  END LOOP;
END;
/

This script appends _UPDATEDLOB to all LOB segments in user tables.

Final Thoughts

The ability to rename LOB segments directly in Oracle Database 23ai marks a significant step forward in database administration. By eliminating complex workarounds, this feature enhances efficiency and ensures database environments remain well-organized. Whether standardizing segment names or adapting to shifting business needs, this capability helps administrators to maintain cleaner, more streamlined data structures easily.

Hope It Helped!
Prashant Dixit