If you began using WordPress prior to version 2.2, you may notice that your database has tables with two different character sets and collations. This is because all database tables created prior to WordPress 2.2 use the latin1 character set and the latin1_swedish_ci collation, and all database tables created after WordPress 2.2 use the utf8 character set and the utf8_general_ci collation. Outside of the obvious visual difference, no hard evidence has ever been submitted to prove that this difference causes any sort of problem. However, numerous random and unrelated issues have apparently been resolved by standardizing the character set and collation across the database. The WordPress Codex provides an article detailing the process of converting database character sets with MySQL commands. If the thought of destroying your entire database simply because you made a typo concerns you, then fear not! There is an easy way to convert your database’s character set using nothing more than phpMyAdmin (available through most hosting providers’ control panel) and a plain text editor.
The following instructions are Mac-specific using the plain text editor Fraise, but they can be easily reinterpreted using any Windows or Linux-based plain text editor.