I recently updated the MediaWiki installation in one of my DreamHost domains from 1.12 to 1.13, and I started to see the following error messages when trying to edit/save pages (the capital letter triplets used for privacy):
A database query syntax error has occurred. This may indicate a bug in the software. The last attempted database query was:
(SQL query hidden)
from within function "Article:getHiddenCategories". MySQL returned error "1146: Table XXX.YYY_page_props' doesn't exist (mysql.ZZZ.AAA)".
After a Google search that yielded only two results, I checked a mediawiki.org page talking about the subject. The (maybe obvious) reason for my error was that I hadn't run the MediaWiki update script, as one should after any upgrade.
The procedures is outlined in this other mediawiki.org page. However there is a little catch: the PHP version (at least in my case) accessible in the shell of the server where my wiki is is 4.4.8, but the MediaWiki update script needs PHP5. No problem, I checked the DreamHost wiki, and found out that for PHP5 I could use the following executable: /usr/local/dh/cgi-system/php5.cgi.