Maybe it helps

    function wpcodex_filter_main_search_post_limits( $limit, $query ) { 	
      return 'LIMIT 0, 100'; 
    } 
    add_filter( 'post_limits', 'wpcodex_filter_main_search_post_limits', 10, 2 );

More: https://codex.wordpress.org/Plugin_API/Filter_Reference/post_limits