Re: "Fuzzy" text search using n-grams (bigrams) -- speed?

From: Bob Badour <>
Date: Wed, 24 Oct 2007 20:48:00 -0300
Message-ID: <471fd9b9$0$14832$>

crazyhorse wrote:
> Hi all,
> Let's suppose I'm writing a website where users search for movie
> titles, and suppose there are 200,000 movies. The site is in PHP/
> MySQL.
> I'd like to implement a "fuzzy" text search so that similar movie
> titles come up in a list no matter if you include all the words or
> even misspell them.
> MySQL's fulltext-search is a first step, but it doesn't cover mis-
> spellings.
> My question is this: suppose I broke down every movie title into
> bigrams (i.e. "Jaws" becomes *j, ja, aw, ws, s*), and store a
> relationship between every bigram and every movie title that includes
> it in a separate table, BIGRAMS. (Will have two fields, "bigram" and
> "movie_id").
> I break down every search string into bigrams. Then, for every search,
> I retrieve all the rows from BIGRAMS that include any of the bigrams
> in the search string. I then calculate COUNT(movie_id) ORDER BY DESC
> and take the top matches.
> Comments? Anybody have experience with this? Does it work? Or would it
> be far too slow? Is there another better solution I'm missing? We're
> talking 200,000 movies, which means BIGRAMS might have 4 million rows
> or so.
> Thanks
> Michael Received on Thu Oct 25 2007 - 01:48:00 CEST

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