mysql like performance boost

MySQL can use an index if your query looks like foo LIKE 'abc%' or foo LIKE 'abc%def%'. It can use the index for any portion or the string before the first wildcard. If you need to match a word anywhere within a string, you might want to consider using FULLTEXT indexes instead.

More detail on indexes: http://dev.mysql.com/doc/refman/5.1/en/mysql-indexes.html

Full text search: http://dev.mysql.com/doc/refman/5.0/en/fulltext-search.html

Well, the simplest optimization would be to have a constant prefix (e.g. "test%" instead of "%test" or "%test%") since that would allow the engine to narrow down the search space using indices. However, that is not possible in all situations.

Sometimes a preprocessing step can turn a wildcard search into an ordinary equality or a fulltext search. You'll gain more by finding a way to structure your data so that it does not require a wildcard search than trying to optimize the latter.