what index should I use?

Question

I'm getting pretty slow performance for a pretty simple statement (3-4 seconds):

SELECT col1,col2,col3 FROM table WHERE fname LIKE '%D%' OR fname LIKE '%S%' ORDER BY DATE(bday) DESC LIMIT 0,100

I have index on fname, another on bday and even a joint index on fname & bday. Here's my explain:

id  select_type  table  type  possible_keys  key  key_len  ref  rows  Extra

1   SIMPLE       table  ALL   NULL           NULL NULL     NULL 95856 Using where; Using filesort

Answer 1

No index will help you here.

When you're using LIKE '%something% it's going to have to look at every row and do the string matching.

Answer 2

As stated no index will help. Personally I'd consider full text search overkill for this and add an other column to the table, fill it in on insert update and index that.

Like is for one offs.