Unicode versions

Although Unicode provides a consistent way of representing text across multiple languages, there are different versions which provide different data sizes for each character.

The following list describes the versions that are supported within HCL Informix® ODBC applications.

UCS-2: ISO encoding standard that maps Unicode characters to 2 bytes each. UCS-2 is the common encoding standard on Windows.
HCL Informix ODBC Driver for IBM® AIX® platforms supports UCS-2 encoding. HCL Informix ODBC Driver for Windows supports only UCS-2.
UCS-4: ISO encoding standard that maps Unicode characters into 4 bytes each.
The HCL Informix ODBC Driver supports UCS-4 on UNIX platforms.
UTF-8: Encoding standard that is based on a single (8 bit) byte. UTF-8 defines a mechanism to transform all Unicode characters into a variable length (1 - 4) encoding of bytes.
The HCL Informix ODBC Driver uses UTF-8 encoding for all UNIX applications that connect to the Data Direct (formerly Merant) driver manager.

The 7-bit ASCII characters have the same encoding under both ASCII and UTF-8. This has the advantage that UTF-8 can be used with much existing software without extensive revision.

Important: In applications that use Unicode, the driver does the work of code set conversion from Unicode to the database locale and vice versa.The UTF-8 is the only type of Unicode code set that can be set as the client locale.