2009/5/26 Brion Vibber brion@wikimedia.org:
Other posts have linked to general directions on tweaking the MySQL search index length limit. You can also upgrade to MediaWiki 1.14 or later, which works around the MySQL server's limit setting internally without any configuration required.
Win!
(mind you, tweaking MySQL settings in 1.11 worked very nicely for the work wiki ... which is of course full to the brim with TLAs.)
- d.