improve statistics mysql query

Author: tijmenbruggeman

src/class-tiny-bulk-optimization.php

@@ -71,12 +71,12 @@ private static function wpdb_retrieve_images_and_metadata( $start_id ) {
 				$wpdb->posts.ID,
 				$wpdb->posts.post_title,
 				$wpdb->postmeta.meta_value,
-				wp_postmeta_file.meta_value AS unique_attachment_name,
 				wp_postmeta_tiny.meta_value AS tiny_meta_value
 			FROM $wpdb->posts
-			LEFT JOIN $wpdb->postmeta
+			INNER JOIN $wpdb->postmeta
 				ON $wpdb->posts.ID = $wpdb->postmeta.post_id
-			LEFT JOIN $wpdb->postmeta AS wp_postmeta_file
+				AND $wpdb->postmeta.meta_key = '_wp_attachment_metadata'
+			INNER JOIN $wpdb->postmeta AS wp_postmeta_file
 				ON $wpdb->posts.ID = wp_postmeta_file.post_id
 					AND wp_postmeta_file.meta_key = '_wp_attached_file'
 			LEFT JOIN $wpdb->postmeta AS wp_postmeta_tiny
@@ -90,8 +90,6 @@ private static function wpdb_retrieve_images_and_metadata( $start_id ) {
 					$wpdb->posts.post_mime_type = 'image/png' OR
 					$wpdb->posts.post_mime_type = 'image/webp'
 				)
-				AND $wpdb->postmeta.meta_key = '_wp_attachment_metadata'
-			GROUP BY unique_attachment_name
 			ORDER BY ID DESC
 			LIMIT " . self::PAGING_SIZE;