AlbumMappper::getForFile is not using an index

[juliushaertl]

The following query does not seem ot use an index and do a full table scan on the albums table:

photos/lib/Album/AlbumMapper.php

Lines 138 to 146 in 2376b7d

	$query = $this->connection->getQueryBuilder();
	$query->select("a.album_id", "name", "user", "location", "created", "last_added_photo")
	->from("photos_albums", "a")
	->leftJoin("a", "photos_albums_files", "p", $query->expr()->eq("a.album_id", "p.album_id"))
	->where($query->expr()->eq('file_id', $query->createNamedParameter($fileId, IQueryBuilder::PARAM_INT)));
	$rows = $query->executeQuery()->fetchAll();
	return array_map(function (array $row) {
	return new AlbumInfo((int)$row['album_id'], $row['user'], $row['name'], $row['location'], (int)$row['created'], (int)$row['last_added_photo']);
	}, $rows);

From a brief look it should be possible to refactor it to query the oc_photos_albums_files first to then get only the albums using an inner join