Uknown meta entries in wp_postmeta

The best way to know which plugin was adding them is to search/grep your installation for occurrences of 'wpAjax' and "wpAjax". If you find none (which is likely, since the oldest is 3 years old) safely delete from wp_postmeta where meta_key like 'wpAjax%', or something along those lines, if the latter statement might match something it shouldn’t… (Don’t forget to flush memcached along the way if you’re using it.)

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