I’m going out on a limb to say MySQL’s full-text indexing and searching features are underused. They appeared in MySQL 3.23.23 (most people are using 4.x, and 5 is in development), but it’s been news to most of the people I know.

Here’s the deal, the MATCH() function can search a full-text index for a string of text (one or more words) and return relevance-ranked results. It’s at the core of the list of related links at the bottom of every post here.

For that query, I put all the tag names into a single variable that might look like this:

$keywords = “mysql database php select full-text search full-text searching docs documentation”

Then I do a select that looks something like this:

SELECT * FROM wp_posts WHERE MATCH(post_title,post_content) AGAINST(’$keywords’);

The docs give a lot more detail, including how to do boolean searches.

tags: boolean search, boolean searches, boolean searching, database, db, docs, documentation, full text, full text index, full text search, full text searching, fulltext, fulltext search, keywords, match(), mysql, rank, relevance, relevance rank, relevance ranked, relevance ranking, search, search full text

Search Engine Watch did a story about how to use Google and Amazon’s tools to search full-text content inside books.

The gist? when you can get to the tools and where they’ve got content, it does a lot to make books as accessible and open as electronic content.

Sort of related: I’ve spoken of Google Print before and there’s more in the Libraries and Networked Information category.

tags: amazon, book search, electronic content, full text content, google, google print, inside books, search engine, search engine watch, search full text, search inside the book