Oracle8i Reference
Release 2 (8.1.6)

Part Number A76961-01





Go to previous page Go to beginning of chapter Go to next page

Initialization Parameters, 112 of 188


Parameter type: 



NLS_SORT = {BINARY | linguistic_definition} 

Parameter class: 

Dynamic. Scope = ALTER SESSION. 

Default value: 

Derived from NLS_LANGUAGE 

Range of values: 

BINARY or any valid linguistic definition name 

NLS_SORT specifies the collating sequence for ORDER BY queries.

  • If the value is BINARY, then the collating sequence for ORDER BY queries is based on the numeric value of characters (a binary sort that requires less system overhead).

  • If the value is a named linguistic sort, sorting is based on the order of the defined linguistic sort. Most (but not all) languages supported by the NLS_LANGUAGE parameter also support a linguistic sort with the same name.


Note: Setting NLS_SORT to anything other than BINARY causes a sort to use a full table scan, regardless of the path chosen by the optimizer. BINARY is the exception because indexes are built according to a binary order of keys. Thus the optimizer can use an index to satisfy the ORDER BY clause when NLS_SORT is set to BINARY. If NLS_SORT is set to any linguistic sort, the optimizer must include a full table scan and a full sort in the execution plan. 

You must use the NLS_SORT operator with comparison operations if you want the linguistic sort behavior.

See Also:


Go to previous page Go to beginning of chapter Go to next page
Copyright © 1996-2000, Oracle Corporation.

All Rights Reserved.