Adaptive Server can have only one default character set, the character set in which data is stored in its databases. When you install Adaptive Server, you specify a default character set.
WARNING! Please read the following carefully and exercise caution when changing the default character set in Adaptive Server. Sybase strongly recommends that you perform backups before you change a default character set.
When you change the default character set in Adaptive Server, you need to convert any existing data to the new default character set. Conversion is unnecessary only if:
There is no user data in the server.
It is acceptable to destroy user data in the server.
You are absolutely certain that data in the server uses only ASCll-7. In this case, you can change the default without first copying your data out of the server.
In all other cases, you must convert the existing data as follows:
Copy the data out using bcp.
Change the default character set.
Use bcp with the appropriate flags for data conversion to copy the data back into the server.
See the Utility Guide for more information about using bcp to copy data.
WARNING! After converting data to a different character set (particularly to UTF-8), the data may be too large for the allocated column size. Re-create the columns affected with a larger size. Refer to the Unidb tool in the Sybase UDK product.
Code conversion between the character set of the existing data and the new default character set must be supported. If it is not, conversion errors will occur and the data will not be converted correctly. See Chapter 8, “Configuring Client/Server Character Set Conversions,” for more information about supported character set conversions.
Even if conversions are supported between the character sets, some errors may occur due to minor differences between the character sets, or because some characters do not have equivalents in other character sets. Rows containing problematic data may not get copied back into the database or data may contain partial or invalid characters.
