EXTENDED DATA TYPES

EXTENDED DATA TYPES

In 12c, the data type VARCHAR2, NAVARCHAR2, and RAW size will support up to 32,767 bytes in contrast to 4,000 and 2,000 in the earlier releases. The extended character size will reduce the use of going for LOB data types, whenever possible. In order to enable the extended character size, you will have to set theMAX_STRING_SIZE initialization database parameter to EXTENDED.

The following procedure need to run to use the extended data types:

1. Shutdown the database
2. Restart the database in UPGRADE mode
3. Modify the parameter: ALTER SYSTEM SET MAX_STRING_SIZE=EXTENDED;
4. Execute utl32k.sql as sysdba : SQL> @?/rdbms/admin/utl32k.sql
5. Shutdown the database
6. Restart the database in READ WRITE mode

In contrast to LOB data types, the extended data types columns in ASSM tablespace management are stored as SecureFiles LOBs, and in non-ASSM tablespace management they stored as BasciFiles LOBs.

Note: Once modified, you can’t change the settings back to STANDARD.