6
You must edit your sql file in the SQL directory for that.
Normally InnoDB is also by default present in the MySQL database services. It offers addtional features to MyISAM. I don't know if MediaWiki is using these features or if it will still be working after the change.
Because I believe your problem lies in the length of the key due to the UTF-8 encoding, it will surprise me if changing to MyISAM will solve your problem.
I would try this:
CREATE TABLE `xoops_mediawiki_categorylinks` (
cl_from int(8) unsigned NOT NULL default '0',
cl_to varchar(255) binary NOT NULL default '',
cl_sortkey varchar(86) binary NOT NULL default '',
cl_timestamp timestamp NOT NULL, UNIQUE KEY
cl_from(cl_from,cl_to), KEY
cl_sortkey(cl_to (240),cl_sortkey), KEY
cl_timestamp(cl_to,cl_timestamp)
) TYPE=InnoDB ;