&& Returns TRUE if A's 2D bounding box intersects B's 2D bounding box. boolean && geometry A geometry B boolean && geography A geography B The && operator returns TRUE if the 2D bounding box of geometry A intersects the 2D bounding box of geometry B. This operand will make use of any indexes that may be available on the geometries. Enhanced: 2.0.0 support for Polyhedral surfaces was introduced. Availability: 1.5.0 support for geography was introduced. &curve_support; &P_support; SELECT tbl1.column1, tbl2.column1, tbl1.column2 && tbl2.column2 AS overlaps FROM ( VALUES (1, 'LINESTRING(0 0, 3 3)'::geometry), (2, 'LINESTRING(0 1, 0 5)'::geometry)) AS tbl1, ( VALUES (3, 'LINESTRING(1 2, 4 6)'::geometry)) AS tbl2; column1 | column1 | overlaps ---------+---------+---------- 1 | 3 | t 2 | 3 | f (2 rows) , , , , , &&& Returns TRUE if A's 3D bounding box intersects B's 3D bounding box. boolean &&& geometry A geometry B The &&& operator returns TRUE if the n-D bounding box of geometry A intersects the n-D bounding box of geometry B. This operand will make use of any indexes that may be available on the geometries. Availability: 2.0.0 &curve_support; &P_support; &T_support; &Z_support; SELECT tbl1.column1, tbl2.column1, tbl1.column2 &&& tbl2.column2 AS overlaps_3d, tbl1.column2 && tbl2.column2 AS overlaps_2d FROM ( VALUES (1, 'LINESTRING Z(0 0 1, 3 3 2)'::geometry), (2, 'LINESTRING Z(1 2 0, 0 5 -1)'::geometry)) AS tbl1, ( VALUES (3, 'LINESTRING Z(1 2 1, 4 6 1)'::geometry)) AS tbl2; column1 | column1 | overlaps_3d | overlaps_2d ---------+---------+-------------+------------- 1 | 3 | t | t 2 | 3 | f | t SELECT tbl1.column1, tbl2.column1, tbl1.column2 &&& tbl2.column2 AS overlaps_3zm, tbl1.column2 && tbl2.column2 AS overlaps_2d FROM ( VALUES (1, 'LINESTRING M(0 0 1, 3 3 2)'::geometry), (2, 'LINESTRING M(1 2 0, 0 5 -1)'::geometry)) AS tbl1, ( VALUES (3, 'LINESTRING M(1 2 1, 4 6 1)'::geometry)) AS tbl2; column1 | column1 | overlaps_3zm | overlaps_2d ---------+---------+-------------+------------- 1 | 3 | t | t 2 | 3 | f | t &< Returns TRUE if A's bounding box overlaps or is to the left of B's. boolean &< geometry A geometry B The &< operator returns TRUE if the bounding box of geometry A overlaps or is to the left of the bounding box of geometry B, or more accurately, overlaps or is NOT to the right of the bounding box of geometry B. This operand will make use of any indexes that may be available on the geometries. SELECT tbl1.column1, tbl2.column1, tbl1.column2 &< tbl2.column2 AS overleft FROM ( VALUES (1, 'LINESTRING(1 2, 4 6)'::geometry)) AS tbl1, ( VALUES (2, 'LINESTRING(0 0, 3 3)'::geometry), (3, 'LINESTRING(0 1, 0 5)'::geometry), (4, 'LINESTRING(6 0, 6 1)'::geometry)) AS tbl2; column1 | column1 | overleft ---------+---------+---------- 1 | 2 | f 1 | 3 | f 1 | 4 | t (3 rows) , , , &<| Returns TRUE if A's bounding box overlaps or is below B's. boolean &<| geometry A geometry B The &<| operator returns TRUE if the bounding box of geometry A overlaps or is below of the bounding box of geometry B, or more accurately, overlaps or is NOT above the bounding box of geometry B. &curve_support; &P_support; This operand will make use of any indexes that may be available on the geometries. SELECT tbl1.column1, tbl2.column1, tbl1.column2 &<| tbl2.column2 AS overbelow FROM ( VALUES (1, 'LINESTRING(6 0, 6 4)'::geometry)) AS tbl1, ( VALUES (2, 'LINESTRING(0 0, 3 3)'::geometry), (3, 'LINESTRING(0 1, 0 5)'::geometry), (4, 'LINESTRING(1 2, 4 6)'::geometry)) AS tbl2; column1 | column1 | overbelow ---------+---------+----------- 1 | 2 | f 1 | 3 | t 1 | 4 | t (3 rows) , , , &> Returns TRUE if A' bounding box overlaps or is to the right of B's. boolean &> geometry A geometry B The &> operator returns TRUE if the bounding box of geometry A overlaps or is to the right of the bounding box of geometry B, or more accurately, overlaps or is NOT to the left of the bounding box of geometry B. This operand will make use of any indexes that may be available on the geometries. SELECT tbl1.column1, tbl2.column1, tbl1.column2 &> tbl2.column2 AS overright FROM ( VALUES (1, 'LINESTRING(1 2, 4 6)'::geometry)) AS tbl1, ( VALUES (2, 'LINESTRING(0 0, 3 3)'::geometry), (3, 'LINESTRING(0 1, 0 5)'::geometry), (4, 'LINESTRING(6 0, 6 1)'::geometry)) AS tbl2; column1 | column1 | overright ---------+---------+----------- 1 | 2 | t 1 | 3 | t 1 | 4 | f (3 rows) , , , << Returns TRUE if A's bounding box is strictly to the left of B's. boolean << geometry A geometry B The << operator returns TRUE if the bounding box of geometry A is strictly to the left of the bounding box of geometry B. This operand will make use of any indexes that may be available on the geometries. SELECT tbl1.column1, tbl2.column1, tbl1.column2 << tbl2.column2 AS left FROM ( VALUES (1, 'LINESTRING (1 2, 1 5)'::geometry)) AS tbl1, ( VALUES (2, 'LINESTRING (0 0, 4 3)'::geometry), (3, 'LINESTRING (6 0, 6 5)'::geometry), (4, 'LINESTRING (2 2, 5 6)'::geometry)) AS tbl2; column1 | column1 | left ---------+---------+------ 1 | 2 | f 1 | 3 | t 1 | 4 | t (3 rows) , , <<| Returns TRUE if A's bounding box is strictly below B's. boolean <<| geometry A geometry B The <<| operator returns TRUE if the bounding box of geometry A is strictly below the bounding box of geometry B. This operand will make use of any indexes that may be available on the geometries. SELECT tbl1.column1, tbl2.column1, tbl1.column2 <<| tbl2.column2 AS below FROM ( VALUES (1, 'LINESTRING (0 0, 4 3)'::geometry)) AS tbl1, ( VALUES (2, 'LINESTRING (1 4, 1 7)'::geometry), (3, 'LINESTRING (6 1, 6 5)'::geometry), (4, 'LINESTRING (2 3, 5 6)'::geometry)) AS tbl2; column1 | column1 | below ---------+---------+------- 1 | 2 | t 1 | 3 | f 1 | 4 | f (3 rows) , , = Returns TRUE if A's bounding box is the same as B's. Uses double precision bounding box. boolean = geometry A geometry B boolean = geography A geography B The = operator returns TRUE if the bounding box of geometry/geography A is the same as the bounding box of geometry/geography B. PostgreSQL uses the =, <, and > operators defined for geometries to perform internal orderings and comparison of geometries (ie. in a GROUP BY or ORDER BY clause). This is cause for a lot of confusion. When you compare geometryA = geometryB it will return true even when the geometries are clearly different IF their bounding boxes are the same. To check for true equality use or This operand will NOT make use of any indexes that may be available on the geometries. &curve_support; &P_support; Changed: 2.0.0 , the bounding box of geometries was changed to use double precision instead of float4 precision of prior. The side effect of this is that in particular points in prior versions that were a little different may have returned true in prior versions and false in 2.0+ since their float4 boxes would be the same but there float8 (double precision), would be different. SELECT 'LINESTRING(0 0, 0 1, 1 0)'::geometry = 'LINESTRING(1 1, 0 0)'::geometry; ?column? ---------- t (1 row) SELECT ST_AsText(column1) FROM ( VALUES ('LINESTRING(0 0, 1 1)'::geometry), ('LINESTRING(1 1, 0 0)'::geometry)) AS foo; st_astext --------------------- LINESTRING(0 0,1 1) LINESTRING(1 1,0 0) (2 rows) -- Note: the GROUP BY uses the "=" to compare for geometry equivalency. SELECT ST_AsText(column1) FROM ( VALUES ('LINESTRING(0 0, 1 1)'::geometry), ('LINESTRING(1 1, 0 0)'::geometry)) AS foo GROUP BY column1; st_astext --------------------- LINESTRING(0 0,1 1) (1 row) -- In versions prior to 2.0, this used to return true -- SELECT ST_GeomFromText('POINT(1707296.37 4820536.77)') = ST_GeomFromText('POINT(1707296.27 4820536.87)') As pt_intersect; --pt_intersect -- f , >> Returns TRUE if A's bounding box is strictly to the right of B's. boolean >> geometry A geometry B The >> operator returns TRUE if the bounding box of geometry A is strictly to the right of the bounding box of geometry B. This operand will make use of any indexes that may be available on the geometries. SELECT tbl1.column1, tbl2.column1, tbl1.column2 >> tbl2.column2 AS right FROM ( VALUES (1, 'LINESTRING (2 3, 5 6)'::geometry)) AS tbl1, ( VALUES (2, 'LINESTRING (1 4, 1 7)'::geometry), (3, 'LINESTRING (6 1, 6 5)'::geometry), (4, 'LINESTRING (0 0, 4 3)'::geometry)) AS tbl2; column1 | column1 | right ---------+---------+------- 1 | 2 | t 1 | 3 | f 1 | 4 | f (3 rows) , , @ Returns TRUE if A's bounding box is contained by B's. boolean @ geometry A geometry B The @ operator returns TRUE if the bounding box of geometry A is completely contained by the bounding box of geometry B. This operand will make use of any indexes that may be available on the geometries. SELECT tbl1.column1, tbl2.column1, tbl1.column2 @ tbl2.column2 AS contained FROM ( VALUES (1, 'LINESTRING (1 1, 3 3)'::geometry)) AS tbl1, ( VALUES (2, 'LINESTRING (0 0, 4 4)'::geometry), (3, 'LINESTRING (2 2, 4 4)'::geometry), (4, 'LINESTRING (1 1, 3 3)'::geometry)) AS tbl2; column1 | column1 | contained ---------+---------+----------- 1 | 2 | t 1 | 3 | f 1 | 4 | t (3 rows) , |&> Returns TRUE if A's bounding box overlaps or is above B's. boolean |&> geometry A geometry B The |&> operator returns TRUE if the bounding box of geometry A overlaps or is above the bounding box of geometry B, or more accurately, overlaps or is NOT below the bounding box of geometry B. This operand will make use of any indexes that may be available on the geometries. SELECT tbl1.column1, tbl2.column1, tbl1.column2 |&> tbl2.column2 AS overabove FROM ( VALUES (1, 'LINESTRING(6 0, 6 4)'::geometry)) AS tbl1, ( VALUES (2, 'LINESTRING(0 0, 3 3)'::geometry), (3, 'LINESTRING(0 1, 0 5)'::geometry), (4, 'LINESTRING(1 2, 4 6)'::geometry)) AS tbl2; column1 | column1 | overabove ---------+---------+----------- 1 | 2 | t 1 | 3 | f 1 | 4 | f (3 rows) , , , |>> Returns TRUE if A's bounding box is strictly above B's. boolean |>> geometry A geometry B The |>> operator returns TRUE if the bounding box of geometry A is strictly to the right of the bounding box of geometry B. This operand will make use of any indexes that may be available on the geometries. SELECT tbl1.column1, tbl2.column1, tbl1.column2 |>> tbl2.column2 AS above FROM ( VALUES (1, 'LINESTRING (1 4, 1 7)'::geometry)) AS tbl1, ( VALUES (2, 'LINESTRING (0 0, 4 2)'::geometry), (3, 'LINESTRING (6 1, 6 5)'::geometry), (4, 'LINESTRING (2 3, 5 6)'::geometry)) AS tbl2; column1 | column1 | above ---------+---------+------- 1 | 2 | t 1 | 3 | f 1 | 4 | f (3 rows) , , ~ Returns TRUE if A's bounding box contains B's. boolean ~ geometry A geometry B The ~ operator returns TRUE if the bounding box of geometry A completely contains the bounding box of geometry B. This operand will make use of any indexes that may be available on the geometries. SELECT tbl1.column1, tbl2.column1, tbl1.column2 ~ tbl2.column2 AS contains FROM ( VALUES (1, 'LINESTRING (0 0, 3 3)'::geometry)) AS tbl1, ( VALUES (2, 'LINESTRING (0 0, 4 4)'::geometry), (3, 'LINESTRING (1 1, 2 2)'::geometry), (4, 'LINESTRING (0 0, 3 3)'::geometry)) AS tbl2; column1 | column1 | contains ---------+---------+---------- 1 | 2 | f 1 | 3 | t 1 | 4 | t (3 rows) , ~= Returns TRUE if A's bounding box is the same as B's. boolean ~= geometry A geometry B The ~= operator returns TRUE if the bounding box of geometry/geography A is the same as the bounding box of geometry/geography B. This operand will make use of any indexes that may be available on the geometries. Availability: 1.5.0 changed behavior &P_support; This operator has changed behavior in PostGIS 1.5 from testing for actual geometric equality to only checking for bounding box equality. To complicate things it also depends on if you have done a hard or soft upgrade which behavior your database has. To find out which behavior your database has you can run the query below. To check for true equality use or and to check for bounding box equality ; operator is a safer option. select 'LINESTRING(0 0, 1 1)'::geometry ~= 'LINESTRING(0 1, 1 0)'::geometry as equality; equality | -----------------+ t | The above can be used to test if you have the new or old behavior of ~= operator. , , <-> Returns the distance between two points. For point / point checks it uses floating point accuracy (as opposed to the double precision accuracy of the underlying point geometry). For other geometry types the distance between the floating point bounding box centroids is returned. Useful for doing distance ordering and nearest neighbor limits using KNN gist functionality. double precision <-> geometry A geometry B The <-> operator returns distance between two points read from the spatial index for points (float precision). For other geometries it returns the distance from centroid of bounding box of geometries. Useful for doing nearest neighbor approximate distance ordering. This operand will make use of any indexes that may be available on the geometries. It is different from other operators that use spatial indexes in that the spatial index is only used when the operator is in the ORDER BY clause. Index only kicks in if one of the geometries is a constant (not in a subquery/cte). e.g. 'SRID=3005;POINT(1011102 450541)'::geometry instead of a.geom Refer to OpenGeo workshop: Nearest-Neighbour Searching for real live example. Availability: 2.0.0 only available for PostgreSQL 9.1+ d | edabbr | vaabbr ------------------+--------+-------- 0 | ALQ | 128 5541.57712511724 | ALQ | 129A 5579.67450712005 | ALQ | 001 6083.4207708641 | ALQ | 131 7691.2205404848 | ALQ | 003 7900.75451037313 | ALQ | 122 8694.20710669982 | ALQ | 129B 9564.24289057111 | ALQ | 130 12089.665931705 | ALQ | 127 18472.5531479404 | ALQ | 002 (10 rows) Then the KNN raw answer: 'SRID=3005;POINT(1011102 450541)'::geometry limit 10;]]> d | edabbr | vaabbr ------------------+--------+-------- 0 | ALQ | 128 5579.67450712005 | ALQ | 001 5541.57712511724 | ALQ | 129A 8694.20710669982 | ALQ | 129B 9564.24289057111 | ALQ | 130 6083.4207708641 | ALQ | 131 12089.665931705 | ALQ | 127 24795.264503022 | ALQ | 124 24587.6584922302 | ALQ | 123 26764.2555463114 | ALQ | 125 (10 rows) Note the misordering in the actual distances and the different entries that actually show up in the top 10. Finally the hybrid: 'SRID=3005;POINT(1011102 450541)'::geometry LIMIT 100) SELECT * FROM index_query ORDER BY d limit 10;]]> d | edabbr | vaabbr ------------------+--------+-------- 0 | ALQ | 128 5541.57712511724 | ALQ | 129A 5579.67450712005 | ALQ | 001 6083.4207708641 | ALQ | 131 7691.2205404848 | ALQ | 003 7900.75451037313 | ALQ | 122 8694.20710669982 | ALQ | 129B 9564.24289057111 | ALQ | 130 12089.665931705 | ALQ | 127 18472.5531479404 | ALQ | 002 (10 rows) , , <#> Returns the distance between bounding box of 2 geometries. For point / point checks it's almost the same as distance (though may be different since the bounding box is at floating point accuracy and geometries are double precision). Useful for doing distance ordering and nearest neighbor limits using KNN gist functionality. double precision <#> geometry A geometry B The <#> KNN GIST operator returns distance between two floating point bounding boxes read from the spatial index if available. Useful for doing nearest neighbor approximate distance ordering. This operand will make use of any indexes that may be available on the geometries. It is different from other operators that use spatial indexes in that the spatial index is only used when the operator is in the ORDER BY clause. Index only kicks in if one of the geometries is a constant e.g. ORDER BY (ST_GeomFromText('POINT(1 2)') <#> geom) instead of g1.geom <#>. Availability: 2.0.0 only available for PostgreSQL 9.1+ ST_GeomFromText('LINESTRING(746149 2948672,745954 2948576, 745787 2948499,745740 2948468,745712 2948438, 745690 2948384,745677 2948319)',2249) As b_dist, ST_Distance(b.geom, ST_GeomFromText('LINESTRING(746149 2948672,745954 2948576, 745787 2948499,745740 2948468,745712 2948438, 745690 2948384,745677 2948319)',2249)) As act_dist FROM bos_roads As b ORDER BY b_dist, b.tlid LIMIT 100) As foo ORDER BY act_dist, tlid LIMIT 10;]]> tlid | mtfcc | b_dist | act_dist -----------+-------+------------------+------------------ 85732027 | S1400 | 0 | 0 85732029 | S1400 | 0 | 0 85732031 | S1400 | 0 | 0 85734335 | S1400 | 0 | 0 85736037 | S1400 | 0 | 0 624683742 | S1400 | 0 | 128.528874268666 85719343 | S1400 | 260.839270432962 | 260.839270432962 85741826 | S1400 | 164.759294123275 | 260.839270432962 85732032 | S1400 | 277.75 | 311.830282365264 85735592 | S1400 | 222.25 | 311.830282365264 (10 rows) , ,