[wp-hackers] Development for 2.x : Improved Search

[Denis de Bernardy]

> > a) Simple : Add MySQL Full Text Indexing to Wordpress and
> > modify the search hooks to use it. Moving to FT indices on 
> > MyISAM tables gives actually quite good serch out of the 
> > gate. (...)
> > 
> > Difficulty: not huge.  Willing to do in full myself.
> 
> This is mostly done already, and MyISAM full text indexing is 
> about as bad as bad can get.
> 
> http://www.semiologic.com/software/search-reloaded/

As additional information, a past version of the plugin did a slightly
better job than the above at the cost of a huge compute power. To spare
yourself some time:

1. Using a FT index on the text-only version of the formatted post excerpt
and content does not improve the results in any significant manner.

2. MySQL has a number of issues that are related to charsets.

These tend to worsen after MySQL 4.1 (at which point they introduced a
collection of new bugs, for good measure). The underlying mess is a
nightmare to sort out.

3. Trying to tweak the results by reworking the raw mysql score can produce
meaningful enhancements but involved a significant overhead.

Things I tried include the keyword order, their presence in the post title,
presence or absence of double quotes to create keyword groups, and later on
the use of a soundex.

I eventually dropped all of these ideas because working around MySQL's lack
of features by using php was simply ridiculous. If you give this a shot
yourself, store your indexes and search procedures in a real database, such
as pgsql.

4. Last but not least, several users sent me messages along the lines of the
following:

"Search reloaded returns results in a random order. Why doesn't it sort
results by date?"


Denis