Configuring Client/Server Character Set Conversions

In a heterogeneous environment, SAP ASE may need to communicate with clients running on different platforms using different character sets.

Although different character sets may support the same language group (for example, ISO 8858-1 and CP 850 support the group 1 languages), they may encode the same characters differently. For example, in ISO 8859-1, the character à is encoded as 0xE0 in hexadecimal. However, in CP 850 the same character is encoded as 0x85 in hexadecimal.

To maintain data integrity between your clients and servers, data must be converted between the character sets. The goal is to ensure that an “a” remains an “a” even when crossing between machine and character set boundaries. This process is known as character set conversion.

• Supported Character Set Conversions
  Character set conversion occurs between a pair of character sets. The supported conversions in any particular client/server system depend on the character sets used by the server and its clients. One type of character set conversion occurs if the server uses a native character set as the default; a different type of conversion is used if the server default is Unicode UTF-8.
• Choosing a Conversion Type
  By default, SAP ASE uses direct conversions to convert data between different character sets.
• Enabling and Disabling Character Set Conversion
  A client that requests a connection identifies its character set to SAP ASE. SAP ASE compares the client character set with its default character set, and if the two names are identical, no conversion is required.
• Error handling in character set conversion
  The SAP ASE character set conversion reports errors when a character exists in the client’s character set but not in the server’s character set, or vice versa.
• Conversions and Changes to Data Lengths
  In some cases, converting data between the server’s character set and the client’s character set results in a change to the length of the data. For example, when the character set on one system uses one byte to represent each character and the character set on the other system requires two bytes per character.
• Specify the Character Set for Utility Programs
  The SAP utility programs assume that the default character set of the client platform is the same character set the client is using.