You can give threads with the simliar tags a heavier "weight" in the ranking. You can do this in sphinx with 2 lines of code or you can write it in PHP. The problem is not "is this possible", but rather "What is the performance hit if...". I haven't looked at MYSQL in a while, so things may have changed, but you should look into Full Text search. Just use this in a few queries and you'll get what you need, but it will be damn slow....it really depends on the size of your DB and expected delay.
You can also apply a few tricks where you only grab the 100 or so most recent threads using plain old MYSQL and THEN do the whole matching on tags/title/etc. Yes it is inaccurate, but you skip the overhead of doing the LIKE % on every row in your DB. You can then tweak the max number of recent threads fetched based on your hardware for optimal results.
The wizard for the original SphinxSearch will install it for you in your web root directory. The "Lite" version installer only generates your config file AFTER you installed sphinx by yourself either using your distro or manually. It does not validate the existence of the installed files, due to people having problems with the apache permissions read/write outside of web root.
2.0.6 -> 2.0.8 have been tested. Sphinx has been pretty good with backwards compatibility.
Are you on windows or linux?
You're right @peregrine . Either compile and install yourself or use the distro (if using sphinxlite). Lite version will not install it. The main sphinx plugin does provide an installer, so that is always an option, however the user should be aware that the the installed files on inside of the www root. Everything else you said above is correct.
Use the stable version on the main downloads site if you are unwilling to expect problems like this.
No, I didn't. See above for the posted solution. If someone could edit that post to make it seem legible, that would be greaaat. Not sure why our editor here is always seems to do that.
Don't use the mangled code above, just use the code in this link: