Built-in character sets

The ASCII character set is the default character set that is used if you do not specify the CHAR_SET index parameter in the CREATE INDEX statement. The ASCII character set includes the numbers 0 through 9, the uppercase letters A through Z, and the lowercase letters a through z. All lowercase letters are mapped internally to uppercase, which means that searches that use the ASCII character set are not case sensitive.

The ISO and OVERLAP_ISO character sets extend the ASCII character set by including many international characters. The OVERLAP_ISO character set maps similar international characters to a single ASCII character.