string_units - Default string units configuration parameter
This parameter specifies the default string units that are used when defining character data types and graphic data types in Unicode databases.
- Configuration type
- Database
- Parameter type
- Configurable online
- Default [range]
- SYSTEM [SYSTEM, CODEUNITS32]
The value of this parameter is used only when the session level global variable NLS_STRING_UNITS is null. The default value of NLS_STRING_UNITS is null if it is not set during that session.
When the string_units configuration
parameter is set to SYSTEM in a Unicode database:
- CHAR, VARCHAR, and CLOB data types that are defined without specifying the CODEUNITS32 keyword default to OCTETS.
- GRAPHIC, VARGRAPHIC, and DBCLOB data types that are defined without specifying the CODEUNITS32 keyword default to CODEUNITS16.
When the string_units configuration
parameter is set to SYSTEM in a non-Unicode database:
- CHAR, VARCHAR, and CLOB data types that are defined without specifying the CODEUNITS32 keyword default to OCTETS.
- GRAPHIC, VARGRAPHIC, and DBCLOB data types that are defined without specifying the CODEUNITS32 keyword have implicit string units of double bytes.
The string_units configuration parameter
can be set to CODEUNITS32 in Unicode databases only.
When the string_units configuration parameter
is set to CODEUNITS32:
- CHAR, VARCHAR, and CLOB data types that are defined without specifying the BYTE or OCTETS keywords default to CODEUNITS32.
- GRAPHIC, VARGRAPHIC, and DBCLOB data types that are defined without specifying the CODEUNITS16 keyword default to CODEUNITS32.