1.200 NLS_COMP
NLS_COMP
specifies the collation behavior of the database session.
Property | Description |
---|---|
Parameter type |
String |
Syntax |
|
Default value |
|
Modifiable |
|
Modifiable in a PDB |
Yes |
Basic |
No |
Values
-
BINARY
Normally, comparisons in the
WHERE
clause and in PL/SQL blocks is binary unless you specify theNLSSORT
function. -
LINGUISTIC
Comparisons for all SQL operations in the
WHERE
clause and in PL/SQL blocks should use the linguistic sort specified in theNLS_SORT
parameter. To improve the performance, you can also define a linguistic index on the column for which you want linguistic comparisons. -
ANSI
A setting of
ANSI
is for backward compatibility; in general, you should setNLS_COMP
toLINGUISTIC
Note:
Unless you explicitly set the value for NLS_COMP
in your initialization parameter file, a default value of NULL is shown in the following views: V$PARAMETER
, V$SYSTEM_PARAMETER
, V$PARAMETER2
, V$SYSTEM_PARAMETER2
, and NLS_INSTANCE_PARAMETERS
. However, the actual default value, and behavior, is BINARY
. Note that you cannot change the default to NULL, because NULL is not among the valid values.
Examples
See Oracle Database Globalization Support Guide for examples of using this parameter.
Note:
The value of this initialization parameter NLS_COMP
is used to initialize the session value of this parameter, which is the actual value referenced by the SQL query processing. This initial value is overridden by a client-side value if the client uses the Oracle JDBC driver or if the client is OCI-based and the NLS_LANG
client setting (environment variable) is defined. The initialization parameter value is, therefore, usually ignored.