NLS_COMP

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Property	Description
Parameter type	String
Syntax	NLS_COMP = { BINARY | LINGUISTIC | ANSI }
Default value	BINARY
Modifiable	ALTER SESSION
Basic	No

NLS_COMP specifies the collation behavior of the database session.

Values:

· BINARY

Normally, comparisons in the WHERE clause and in PL/SQL blocks is binary unless you specify the NLSSORT function.

· LINGUISTIC

Comparisons for all SQL operations in the WHERE clause and in PL/SQL blocks should use the linguistic sort specified in the NLS_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 backwards compatibility; in general, you should set NLS_COMP to LINGUISTIC

Note:

1. 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.

2. Query for the current value of the parameter

select name, value, isdefault, isses_modifiable, issys_modifiable,

isinstance_modifiable, isdeprecated, description

from v$parameter where upper(name) = ‘NLS_COMP’;

NAME	VALUE	IS DEFAULT	ISSES_ MODIFIABLE	ISSYS_ MODIFIABLE	ISINSTANCE_ MODIFIABLE	IS DEPRECATED	DESCRIPTION
nls_comp		TRUE	TRUE	FALSE	FALSE	FALSE	NLS comparison

Oracle initializatoin parameters