WordPress Search running very slowly

You should post the code for the search. Could be the search code itself (Custom). This is what I like to do as I can get better results but it can be slow for larger sites. If it is the default code then you might want to look into a Cache system to keep queries to a minimum and less hard on the hosting environment. Or just upgrade your hosting!

The sql query for search is in /wp-includes/query.php

// If a search pattern is specified, load the posts that match
                                if ( !empty($q['s']) ) {

                                                // added slashes screw with quote grouping when done early, so done later
                                                $q['s'] = stripslashes($q['s']);
                                                if ( !empty($q['sentence']) ) {
                                                              $q['search_terms'] = array($q['s']);

                                                } else {

                                                                preg_match_all('/".*?("|$)|((?<=[\\s",+])|^)[^\\s",+]+/', $q['s'], $matches);

                                                                $q['search_terms'] = array_map('_search_terms_tidy', $matches[0]);

                                                }

                                                $n = !empty($q['exact']) ? '' : '%';

                                                $searchand = '';

                                                foreach( (array) $q['search_terms'] as $term ) {

                                                                $term = esc_sql( like_escape( $term ) );

                                                                $search .= "{$searchand}(($wpdb->posts.post_title LIKE '{$n}{$term}{$n}') OR ($wpdb->posts.post_content LIKE '{$n}{$term}{$n}'))";

                                                                $searchand = ' AND ';

                                                }

                                                if ( !empty($search) ) {

                                                                $search = " AND ({$search}) ";

                                                                if ( !is_user_logged_in() )

                                                                                $search .= " AND ($wpdb->posts.post_password = '') ";

                                                }

                                }

And in wp-content/themes/quote/inc/improved-search.php it’s the code that will search in topics and authors

<?php

// search all taxonomies, based on: https://projects.jesseheap.com/all-projects/wordpress-plugin-tag-search-in-wordpress-23

function taxonomies_search_groupby($groupby){

  global $wpdb;

  // we need to group on post ID

  $groupby_id = "{$wpdb->posts}.ID";

  if(!is_search() || strpos($groupby, $groupby_id) !== false) return $groupby;

  // groupby was empty, use ours

  if(!strlen(trim($groupby))) return $groupby_id;

  // wasn't empty, append ours

  return $groupby.", ".$groupby_id;

}

function taxonomies_search_join($join){

  global $wpdb;

  if (is_search())

    $join .= "LEFT JOIN {$wpdb->term_relationships} tr ON {$wpdb->posts}.ID = tr.object_id INNER JOIN {$wpdb->term_taxonomy} tt ON tt.term_taxonomy_id=tr.term_taxonomy_id INNER JOIN {$wpdb->terms} t ON t.term_id = tt.term_id";

  return $join;

}

function taxonomies_search_where($where){

  global $wpdb;

  if (is_search())

                $where .= "OR (t.name LIKE '%".str_replace(array(' quotes',' quote'),'',get_search_query())."%' AND {$wpdb->posts}.post_status = 'publish')";

  return $where;

}

add_filter('posts_where','taxonomies_search_where');

add_filter('posts_join', 'taxonomies_search_join');

add_filter('posts_groupby', 'taxonomies_search_groupby');

?>

[Moderator Note: Please post code or markup snippets between backticks or use the code button. Or better still – use the pastebin. As it stands, your code may now have been permanently damaged/corrupted by the forum’s parser.]