Neoview Character Sets Administrator's Guide (R2.4, R2.5)

1 Introduction to Neoview Character Sets
The Neoview Character Sets feature allows clients to store data encoded in any supported
character set, including multibyte data, into SQL database objects on the Neoview platform.
Clients include customer applications running on other systems and users accessing Neoview
client applications from client workstations. When configured to do so, translation functions in
the Neoview ODBC and JDBC drivers or in the Neoview Transporter or Neoview Loader convert
the client locale character data into the character set encoding that can be stored in and retrieved
from the Neoview database.
The Neoview platform enforces the use of compatible and mappable character sets between
client locales and the Neoview database by ensuring that:
Character data sent to the Neoview database from customer applications is successfully
converted to the character encoding required for the Neoview database.
As needed, character data retrieved from the Neoview database is converted to a character
set that is compatible with the retrieving customer application or other client locale.
Incompatible characters from Neoview client and server components are managed as follows:
If a user attempts to store incompatible character data in the Neoview database, that data
is rejected and an error is returned to the user.
If character data retrieved from the Neoview database is returned to a client locale that is
configured with an incompatible character set, the incompatible characters are replaced with
replacement characters (by default, question marks) and a warning message is returned
whenever possible.
The objective of the Neoview Character Sets feature is to perform transparent and successful
mapping of character data sent back and forth between customer applications and the Neoview
database.
Neoview Character Set Configurations, Column Character Definitions,
and Character Sets
Because the terminology overlaps, it is important to clearly understand the differences between
Neoview character set configurations, column character set definitions, and the character sets
that are actually stored in Neoview database character columns.
For this release, customers can choose one of these Neoview character set configurations:
ISO88591 configuration
SJIS configuration
Unicode configuration
For detailed descriptions of these configurations, see “Neoview Character Set Configurations”
(page 16).
In any of these three configurations, character data must be stored in columns defined with an
ISO88591 column character set definition or a UCS2 column character set definition using a
character set that is supported by the Neoview database. ISO88591 columns store character data
in single-byte containers. UCS2 columns store character data in double-byte containers.
You specify these values when you use an SQL statement to create a table and define its character
columns. To identify the column character set definition for a column, you specify the value
CHARACTER SET ISO88591 or CHARACTER SET UCS2. To define the character set encoding
for a character string literal stored in that column, you specify the literal prefix _ISO88591,
_UCS2, or N.
It is important to distinguish between the column character set definition and the actual character
set encoding of the data stored in the column, because they are not always the same. UCS2
columns do not always store UCS2-encoded data, and ISO88591 columns can store any supported
Neoview Character Set Configurations, Column Character Definitions, and Character Sets 13