What's the difference between utf8_general_ci and utf8_unicode_ci?

Question

Between utf8_general_ci and utf8_unicode_ci, are there any differences in terms of performance?

Answer 1

Some details (PL)

As we can read here (Peter Gulutzan) there is difference on sorting/comparing polish letter "Ł" (L with stroke - html esc: Ł) (lower case: "ł" - html esc: ł) - we have following assumption:

utf8_polish_ci      Ł greater than L and less than M
utf8_unicode_ci     Ł greater than L and less than M
utf8_unicode_520_ci Ł equal to L
utf8_general_ci     Ł greater than Z

In polish language letter Ł is after letter L and before M. No one of this coding is better or worse - it depends of your needs.