WordPress extend results append POST in Tag list

functions.php

function extend_search_tag($query){
		global $wpdb;
		if(is_tag()){
			// GET LIMIT RANGE OF ORIGINAL SQL QUERY
			preg_match('@(LIMIT [0-9]+, [0-9]+)@', $query, $limitData);
			$limit = $limitData[1];
			
			$query = str_replace($limit, '', $query);
			$query = str_replace('SQL_CALC_FOUND_ROWS', '', $query);
				
			// SELECT GET POST UNION ON ORIGINAL QUERY
			$query_most_views = "SELECT $wpdb->posts.* FROM $wpdb->posts INNER JOIN $wpdb->postmeta ON ( $wpdb->posts.ID = $wpdb->postmeta.post_id ) WHERE 1=1  AND ( $wpdb->postmeta.meta_key = 'views' ) AND $wpdb->posts.post_type = 'post' AND ($wpdb->posts.post_status = 'publish') ORDER BY $wpdb->postmeta.meta_value+0 DESC LIMIT 0, 160";
				
			// CREATE NEW SQL QUERY WITH UNION
			$query = "SELECT SQL_CALC_FOUND_ROWS UnionPost.* FROM (({$query}) UNION ({$query_most_views})) as UnionPost {$limit}";
				
		}
		
		return $query;
	}
	add_filter( 'posts_request', 'extend_search_tag' );