040000 tree a859f795fdac0dcf0ef4e4cb221262356412f0a8	external-indexing
040000 tree 975ab607e6860223918f0e40345c6a012ba6b940	highly-open-highly-nested
040000 tree 1a437d787ad421f13e5580b2708971802288ce0d	index-join
040000 tree 6024aeeecc5790c0dc5bfc1e37b981dc0292e853	index-leftouterjoin
040000 tree 87f647c2c330b89a3b97cd5ff5cc33f71da55a1b	index-selection