|Oracle9i SQL Reference
Release 2 (9.2)
Part Number A96540-02
DECOMPOSE is valid only for Unicode characters.
DECOMPOSE takes as its argument a string in any datatype and returns a Unicode string after decomposition in the same character set as the input. For example, an o-umlaut codepoint will be returned as the "o" codepoint followed by an umlaut codepoint.
stringcan be any of the datatypes
CANONICALcauses canonical decomposition, which allows recomposition (for example, with the
COMPOSEfunction) to the original string. This is the default.
COMPATIBILITYcauses decomposition in compatibility mode. In this mode, recomposition is not possible. This mode is useful, for example, when decomposing half-width and full-width katakana characters, where recomposition might not be desirable without external formatting or style information.
Oracle9i Database Concepts for information on Unicode character sets and character semantics
The following example decomposes the string "Châteaux" into its component codepoints: