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
- 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.