Sybase Adaptive Server IQ 12.4.2, Administration And Performance Manual

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Understanding character set translation
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Connection strings and character sets
Connection strings present a special case for character set translation. The
connection string is parsed by the client library, in order to locate or start a
database server. This parsing is done with no knowledge of the server character
set or language.
The interface library parses the connection string as follows:
1 It is broken down into its keyword = value components. This can be done
independently of character set, as long as you do not use the curly braces
{} around CommLinks parameters. Instead, use the recommended
parentheses (). Curly braces are valid follow bytes in some multi-byte
character sets.
2 The server is located. The server name is interpreted according to the
character set of the client machine. In the case of Windows operating
systems, the ANSI character set is used. Extended chars can be used unless
they cause character set conversion issues between client and server
machine.
For maximum compatibility among different machines, you should use
server names built from ASCII characters 1 to 128 , using no punctuation
characters. Server names are truncated at 40 characters.
3 The DatabaseName or DatabaseFile parameter is interpreted in the
database server character set.
4 Once the database is located, the remaining connection parameters are
interpreted according to its character set.
Avoiding character-set translation
There is a performance cost associated with character set translation. If you can
set up an environment such that no character set translation is required, then
you do not have to pay this cost, and your setup is simpler to maintain.
If you work with a single-byte character set and are concerned only with seven-
bit ASCII characters (values 1 through 127), then you do not need character set
translation. Even if the code pages are different in the database and on the client
operating system, they are compatible over this range of characters. Many
English-language installations will meet these requirements.
If you do require use of extended characters, there are other steps you may be
able to take: