search produces "fatal error" for empty input

Empty input crashes the search if also all categories are checked. Searching within one category, for example people, suggests that all entries are supposed to be shown as a result. Presumably, the result set is too large for the memory limits of the PHP configuration:

Fatal error: Allowed memory size of 16777216 bytes exhausted (tried to allocate 122880 bytes) in /var/www/labjam/app/production/application/views/toptables/search_results_view.php on line 194