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Question

I'm using a MySQL db with a full-text index of the two fields (name and aliases).

It is a videogames database

codice:

SELECT name,MATCH (name,aliases) AGAINST ('inFamous: Second Son') AS relevance
FROM games_search
ORDER BY relevance DESC;

With this query I get the following results

codice:

inFamous 2                     9.150630950927734
inFamous: Second Son           9.150630950927734
inFamous                       8.947185516357422
inFamous: Festival of Blood    8.947185516357422

Why the first two results have the same relevance?

Answer 1

Full text search in MySQL ignores two types of words: stop words and words shorted than some threshhold.

You can read the list of stop words here . Of particular interest in your case is the word 'second' .

By default, only words with 4 characters or longer are kept for search purposes. Hence, 'son' is ignored. So, your query is equivalent to:

SELECT name, MATCH (name,aliases) AGAINST ('inFamous:') AS relevance
FROM games_search
ORDER BY relevance DESC;

I am not sure why these are higher than the last two. I speculate that the relevancy is treating a perfect match (minus stop words and short words) as slightly higher than an imperfect match.