The CONVERT function generally supports conversion between any two known Oracle character sets. Check Appendix A of the Database Globalization Support Guide for the list of these character sets. However, the CONVERT function takes a VARCHAR2 input and produces a VARCHAR2 result. Both cannot be valid values in the database character set at the same time. Therefore, the CONVERT function should be used only for special repair tasks. If you need to temporarily store or process a value in a character set different from the database character set, you should use the RAW data type and the functions from the package UTL_RAW.