1This directory holds configuration files that enable MySQL to work with 2different character sets. It contains: 3 4charset_name.xml 5 Each charset_name.xml file contains information for a simple character 6 set. The information in the file describes character types, 7 lower- and upper-case equivalencies and sorting orders for the 8 character values in the set. 9 10Index.xml 11 The Index.xml file lists all of the available charset configurations, 12 including collations. 13 14 Each collation must have a unique number. The number is stored 15 IN THE DATABASE TABLE FILES and must not be changed. 16 17 The max-id attribute of the <charsets> element must be set to 18 the largest collation number. 19 20Compiled in or configuration file? 21 When should a character set be compiled in to MySQL's string library 22 (libmystrings), and when should it be placed in a charset_name.xml 23 configuration file? 24 25 If the character set requires the strcoll functions or is a 26 multi-byte character set, it MUST be compiled in to the string 27 library. If it does not require these functions, it should be 28 placed in a charset_name.xml configuration file. 29 30 If the character set uses any one of the strcoll functions, it 31 must define all of them. Likewise, if the set uses one of the 32 multi-byte functions, it must define them all. See the manual for 33 more information on how to add a complex character set to MySQL. 34 35Syntax of configuration files 36 The syntax is very simple. Words in <map> array elements are 37 separated by arbitrary amounts of whitespace. Each word must be a 38 number in hexadecimal format. The ctype array has 257 words; the 39 other arrays (lower, upper, etc.) take up 256 words each after that. 40