Geospatial/Geometry Functions

Five types of geospatial functions are available in Kinetica:

Scalar Functions - apply a geospatial function at the record level to WKT or X/Y data
Enhanced Performance Scalar Functions - apply performance-optimized geospatial functions to X/Y data
Aggregate Functions - apply a geospatial function across groups of records to WKT or X/Y data
Track Functions - apply scalar & aggregate functions to track-based data
H3 Functions - apply H3 gridding functions to WKT or X/Y data

Use ST_ISVALID to determine if a geometry object is valid. The functions below work best with valid geometry objects.
Use the REMOVE_NULLABLE function to remove any nullable column types that could result from calculating a derived column (e.g., as in Projections) using one of the functions below.

Enhanced Performance Scalar Functions

The functions below all compare x and y coordinates to geometry objects (or vice versa), thus increasing their performance in queries. Each of these functions have a geometry-to-geometry version listed in the next section.

STXY_CONTAINS(geom, x, y)

Returns 1 (true) if geom contains the x and y coordinate, e.g. lies in the interior of geom. The coordinate cannot be on the boundary and also be contained because geom does not contain its boundary

STXY_CONTAINSPROPERLY(geom, x, y)

Returns 1 (true) if the x and y coordinate intersects the interior of geom but not the boundary (or exterior) because geom does not contain its boundary but does contain itself

STXY_COVEREDBY(x, y, geom)

Returns 1 (true) if the x and y coordinate is covered by geom

STXY_COVERS(geom, x, y)

Returns 1 (true) if geom covers the x and y coordinate

STXY_DISJOINT(x, y, geom)

Returns 1 (true) if the given x and y coordinate and the geometry geom do not spatially intersect.

STXY_DISTANCE (x, y, geom[, solution])

Calculates the minimum distance between the given x and y coordinate and geom using the specified solution type. Solution types available:

0 (default) - Euclidean; returns 2-D Euclidean distance
1 - Haversine; returns minimum sphere distance in meters
2 - Vincenty; returns minimum spheroid distance in meters, more accurate than Haversine but slower performance

If the x and y coordinate and geom intersect (verify using ST_INTERSECTS), the distance will always be 0.

STXY_DWITHIN (x, y, geom, distance[, solution])

Returns 1 (true) if the x and y coordinate is within the specified distance from geom using the specified solution type. Solution types available:

0 (default) - Euclidean; uses degrees to calculate distance
1 - Sphere; uses meters to calculate sphere distance
2 - Spheroid; uses meters to calculate spheroid distance

STXY_ENVDWITHIN (x, y, geom, distance[, solution])

Returns 1 (true) if the x and y coordinate is within the specified distance from the bounding box of geom using the specified solution type. Solution types available:

0 (default) - Euclidean; uses degrees to calculate distance
1 - Sphere; uses meters to calculate distance

STXY_ENVINTERSECTS(x, y, geom)

Returns 1 (true) if the bounding box of the given geometry geom intersects the x and y coordinate.

STXY_GEOHASH(x, y[, precision])

Returns a hash string representation of the given x and y coordinates with specified precision (the length of the resulting geohash string). The longer the precision, the more precise the hash is. By default, precision is set to 20; the max for precision is 32.See Geohash for an example.

STXY_H3(x, y, resolution)

Alias for H3_XYTOCELL; see H3 Functions.

STXY_INTERSECTION(x, y, geom)

Returns the shared portion between the x and y coordinate and the given geometry geom, i.e. the point itself.

STXY_INTERSECTS(x, y, geom)

Returns 1 (true) if the x and y coordinate and geom intersect in 2-D.

STXY_TOUCHES(x, y, geom)

Returns 1 (true) if the x and y coordinate and geometry geom have at least one point in common but their interiors do not intersect. If geom is a GEOMETRYCOLLECTION, a 0 is returned regardless if the point and geometry touch

STXY_WITHIN(x, y, geom)

Returns 1 (true) if the x and y coordinate is completely inside the geom geometry i.e., not on the boundary

Scalar Functions

DIST(x1, y1, x2, y2)

Computes the Euclidean distance (in degrees), i.e. SQRT( (x1-x2)*(x1-x2) + (y1-y2)*(y1-y2) ).

GEODIST(lon1, lat1, lon2, lat2)

Computes the geographic great-circle distance (in meters) between two lat/lon points.

GEOHASH_DECODE_LATITUDE(geohash)

Decodes a given geohash and returns the latitude value for the given hash string. Supports a maximum geohash character length of 16.

GEOHASH_DECODE_LONGITUDE(geohash)

Decodes a given geohash and returns the longitude value for the given hash string. Supports a maximum geohash character length of 16.

GEOHASH_ENCODE(lat, lon, precision)

Encodes a given coordinate pair and returns a hash string with a given precision. The maximum precision is 15.

GEOMETRY(wkt)

Alias for ST_GEOMFROMTEXT(wkt)

ST_ADDPOINT (linestring, point[, position])

Adds a given point geometry to the given linestring geometry at the specified position, which is a 0-based index. If no position is specified, the point will be added to the end.

ST_ALMOSTEQUALS (geom1, geom2[, decimal])

Returns 1 (true) if given geometries, geom1 and geom2, are almost spatially equal within the given amount of decimal scale. Note that geometries will still be considered equal if the decimal scale for the geometries is within a half order of magnitude of each other; e.g., if decimal is set to 2, then POINT(63.4 123.45) and POINT(63.4 123.454) are equal, but POINT(63.4 123.45) and POINT(63.4 123.459) are not equal. The geometry types must match to be considered equal.If no decimal scale is specified, a default scale of 6 will be applied.

ST_AREA(geom[, solution])

Returns the area of the given geometry geom if it is a POLYGON or MULTIPOLYGON using the specified solution type. Returns 0 if the input geometry type is (MULTI)POINT or (MULTI)LINESTRING. Solution types available:

0 (default) - 2D Euclidean area
1 - curved surface area on a sphere in square meters
2 - curved surface area on a spheroid in square meters

ST_AZIMUTH(geom1, geom2)

Returns the azimuth in radians defined by the segment between two POINTs, geom1 and geom2. Returns a null if the input geometry type is MULTIPOINT, (MULTI)LINESTRING, or (MULTI)POLYGON.

ST_BOUNDARY(geom)

Returns the closure of the combinatorial boundary of a given geometry geom. Returns an empty geometry if geom is an empty geometry. Returns a null if geom is a GEOMETRYCOLLECTION

ST_BOUNDINGDIAGONAL(geom)

Returns the diagonal of the given geometry’s (geom) bounding box.

ST_BUFFER (geom, radius[, style[, solution]])

Returns a geometry that represents all points whose distance from the given geometry geom is less than or equal to the given distance radius. The radius units can be specified by the solution type (default is in degrees) and the radius is created in the provided style. The style options are specified as a list of blank-separated key-value pairs, e.g., 'quad_segs=8 endcap=round'. If an empty style list ('') is provided, the default settings will be used. The style parameter must be specified to provide a solution type.Available style options:

quad_segs - the number of segments used to approximate a quarter circle (default is 8)
endcap - the endcap style of the buffer (default is round); options are round, flat (or butt), and square
join - the join style of the buffer (default is round); options are round, mitre (or miter), and bevel
mitre_limit - the mitre ratio limit expressed as a floating-point number (miter_limit is also acceptable)

Available solution types:

0 (default) - 2D Euclidean radius distance in degrees
1 - curved surface radius distance on a sphere in meters
2 - curved surface radius distance on a spheroid in meters

To create a 5-meter buffer around geom using the default styles: ST_BUFFER(geom, 5, '', 1). To create a 5-foot (converting feet to meters) buffer around geom using the following styles: ST_BUFFER(geom, 5*0.3048,'quad_segs=4 endcap=flat', 1)

ST_BUFFERBYCOMPONENT (geom, radius[, style[, solution]])

Returns a buffered geometry similar to the output of ST_BUFFER using the same parameters. The only difference is the buffered geometry is calculated by independently buffering each individual component and then the buffered components are dissolved (i.e. unioned) together to produce the final output. This can produce very similar (but not identical) results to ST_BUFFER but will often run much faster.

ST_CENTROID(geom)

Calculates the center of the given geometry geom as a POINT. For (MULTI)POINTs, the center is calculated as the average of the input coordinates. For (MULTI)LINESTRINGs, the center is calculated as the weighted length of each given LINESTRING. For (MULTI)POLYGONs, the center is calculated as the weighted area of each given POLYGON. If geom is an empty geometry, an empty GEOMETRYCOLLECTION is returned

ST_CLIP(geom1, geom2)

Returns the geometry shared between given geometries geom1 and geom2

ST_CLOSESTPOINT (geom1, geom2[, solution])

Calculates the 2-D POINT in geom1 that is closest to geom2 using the specified solution type. If geom1 or geom2 is empty, a null is returned. Solution types available:

0 (default) - Euclidean; calculates the closest point using 2-D Euclidean distance
1 - Haversine; calculates the closest point using sphere distance in meters
2 - Vincenty; returns minimum spheroid distance in meters, more accurate than Haversine but slower performance

ST_COLLECT(geom1, geom2)

Returns a MULTI* or GEOMETRYCOLLECTION comprising geom1 and geom2. If geom1 and geom2 are the same, singular geometry type, a MULTI* is returned, e.g., if geom1 and geom2 are both POINTs (empty or no), a MULTIPOINT is returned. If geom1 and geom2 are neither the same type nor singular geometries, a GEOMETRYCOLLECTION is returned.

ST_COLLECTIONEXTRACT (collection, type)

Returns only the specified type from the given geometry collection. Type is a number that maps to the following:

1 = POINT
2 = LINESTRING
3 = POLYGON

ST_COLLECTIONHOMOGENIZE(collection)

Returns the simplest form of the given collection, e.g., a collection with a single POINT will be returned as POINT(x y), and a collection with multiple individual points will be returned as a MULTIPOINT.

ST_CONCAVEHULL (geom, target_percent[, allow_holes])

Returns a potentially concave geometry that encloses all geometries found in the given geom set. Use target_percent (values between 0 and 1) to determine the percent of area of a convex hull the concave hull will attempt to fill; 1 will return the same geometry as an ST_CONVEXHULL operation. Set allow_holes to 1 (true) to allow holes in the resulting geometry; default value is 0 (false). Note that allow_holes is independent of the area of target_percent.

ST_CONTAINS(geom1, geom2)

Returns 1 (true) if no points of geom2 lie in the exterior of geom1 and at least one point of geom2 lies in the interior of geom1. Note that geom1 does not contain its boundary but does contain itself.

ST_CONTAINSPROPERLY(geom1, geom2)

Returns 1 (true) if geom2 intersects the interior of geom1 but not the boundary (or exterior). Note that geom1 does not contain its boundary but does contain itself.

ST_CONVEXHULL(geom)

Returns the minimum convex geometry that encloses all geometries in the given geom set.

ST_COORDDIM(geom)

Returns the coordinate dimension of the given geom, e.g., a geometry with x, y, and z coordinates would return 3.

ST_COVEREDBY(geom1, geom2)

Returns 1 (true) if no point in geom1 is outside geom2.

ST_COVERS(geom1, geom2)

Returns 1 (true) if no point in geom2 is outside geom1.

ST_CROSSES(geom1, geom2)

Returns 1 (true) if the given geometries, geom1 and geom2, spatially cross, meaning some but not all interior points in common. If geom1 and/or geom2 are a GEOMETRYCOLLECTION, a 0 is returned regardless of if the two geometries cross

ST_DIFFERENCE(geom1, geom2)

Returns a geometry that represents the part of geom1 that does not intersect with geom2.

ST_DIMENSION(geom)

Returns the dimension of the given geometry geom, which is less than or equal to the coordinate dimension. If geom is a single geometry, a 0 is for POINT, a 1 is for LINESTRING, and a 2 is for POLYGON. If geom is a collection, it will return the largest dimension from the collection. If geom is empty, 0 is returned.

ST_DISJOINT(geom1, geom2)

Returns 1 (true) if the given geometries, geom1 and geom2, do not spatially intersect.

ST_DISTANCE(geom1, geom2[, solution])

Calculates the minimum distance between the given geometries, geom1 and geom2, using the specified solution type. Solution types available:

0 (default) - Euclidean; returns 2-D Euclidean distance
1 - Haversine; returns minimum sphere distance in meters
2 - Vincenty; returns minimum spheroid distance in meters, more accurate than Haversine but slower performance

If geom1 and geom2 intersect (verify using ST_INTERSECTS), the distance will always be 0.

ST_DISTANCEPOINTS (x1, y1, x2, y2[, solution])

Calculates the minimum distance between the given points, x1, y1 and x2, y2, using the specified solution type. Solution types available:

0 (default) - Euclidean; returns 2-D Euclidean distance
1 - Haversine; returns minimum sphere distance in meters
2 - Vincenty; returns minimum spheroid distance in meters, more accurate than Haversine but slower performance

ST_DFULLYWITHIN (geom1, geom2, distance[, solution])

Returns 1 (true) if the maximum distance between geometries geom1 and geom2 is less than or equal to the specified distance of each other using the specified solution type. If geom1 or geom2 is null, 0 (false) is returned. Solution types available:

0 (default) - Euclidean; uses degrees to calculate distance
1 - Sphere; uses meters to calculate distance
2 - Spheroid; uses meters to calculate distance, more accurate than sphere but slower performance

ST_DWITHIN (geom1, geom2, distance[, solution])

Returns 1 (true) if the minimum distance between geometries geom1 and geom2 is within the specified distance of each other using the specified solution type. Solution types available:

0 (default) - Euclidean; uses degrees to calculate distance
1 - Sphere; uses meters to calculate distance
2 - Spheroid; uses meters to calculate distance, more accurate than sphere but slower performance

ST_ELLIPSE(x, y, height, width)

Returns an ellipse using the following values:

x - the x coordinate or longitude used to center the ellipse
y - the y coordinate or latitude used to center the ellipse
height - the height of the ellipse (in degrees)
width - the width of the ellipse (in degrees)

ST_ENDPOINT(geom)

Returns the last point of the given geom as a POINT if it’s a LINESTRING. If geom is not a LINESTRING, null is returned.

ST_ENVDWITHIN (geom1, geom2, distance[, solution])

Returns 1 (true) if geom1 is within the specified distance of the bounding box of geom2 using the specified solution type. Solution types available:

0 (default) - Euclidean; uses degrees to calculate distance
1 - Sphere; uses meters to calculate distance

ST_ENVELOPE(geom)

Returns the bounding box of a given geometry geom.

ST_ENVINTERSECTS(geom1, geom2)

Returns 1 (true) if the bounding box of the given geometries, geom1 and geom2, intersect.

ST_EQUALS(geom1, geom2)

Returns 1 (true) if the given geometries, geom1 and geom2, are spatially equal. Note that order does not matter.

ST_EQUALSEXACT (geom1, geom2[, tolerance])

Returns 1 (true) if the given geometries, geom1 and geom2, are almost spatially equal within some given tolerance. If the values within the given geometries are within the tolerance value of each other, they’re considered equal, e.g., if tolerance is 2, POINT(1 1) and POINT(1 3) are considered equal, but POINT(1 1) and POINT(1 3.1) are not. Note that the geometry types have to match for them to be considered equal. The default tolerance is 0, which makes this function effectively equivalent to ST_EQUALS(geom1, geom2) in the default case.

ST_ERASE(geom1, geom2)

Returns the result of erasing a portion of geom1 equal to the size of geom2.

ST_EXPAND(geom, units)

Returns the bounding box expanded in all directions by the given units of the given geom. The expansion can also be defined for separate directions by providing separate parameters for each direction, e.g., ST_EXPAND(geom, unitsx, unitsy, unitsz, unitsm).

ST_EXPANDBYRATE(geom, rate)

Returns the bounding box expanded by a given rate (a ratio of width and height) for the given geometry geom. The rate must be between 0 and 1.

ST_EXTERIORRING(geom)

Returns a LINESTRING representing the exterior ring of the given POLYGON geom

ST_FORCE2D(geom)

Returns the 2-dimensional version (e.g., X and Y coordinates) of geom, the provided geometry or set of geometries (e.g., via GEOMETRYCOLLECTION or WKT column name).

ST_FORCE3D(geom[, z])

Returns the 3-dimensional version (e.g., X, Y, and Z coordinates) of geom, a provided geometry or set of geometries (e.g., via GEOMETRYCOLLECTION or WKT column name), using z as the geometry’s new z-value. The provided z-values can also be derived from a numeric column. If no z is provided, a 0 will be applied.

If a WKT column is provided for geom and a numeric column is provided for z, the z values will be matched to the provided geometries by row in the source table. If a singular geometry is provided for geom and a column is provided for z, three-dimensional versions of the provided geometry will be returned for each z value found in the provided z column. If columns are provided for both geom and z and nulls are present in either column, the row containing null values will be skipped in the results.

ST_GENERATEPOINTS(geom, num)

Creates a MULTIPOINT containing a number num of randomly generated points within the boundary of geom.

ST_GEOHASH(geom[, precision])

Returns a hash string representation of the given geometry geom with specified precision (the length of the resulting geohash string). The longer the precision, the more precise the hash is. By default, precision is set to 20; the max for precision is 32. Returns null if geom is an empty geometry.See Geohash for an example.

The value returned will not be a geohash of the exact geometry but a geohash of the centroid of the given geometry

ST_GEOMETRYFROMTEXT(wkt)

Alias for ST_GEOMFROMTEXT(wkt)

ST_GEOMETRYN(geom, index)

Returns the index geometry back from the given geom geometry. The index starts from 1 and goes to the number of geometries in geom.

ST_GEOMETRYTYPE(geom)

Returns the type of geometry from the given geom.

ST_GEOMETRYTYPEID(geom)

Returns the type ID of from geom. Type and ID mappings:

POINT = 0
LINESTRING = 1
POLYGON = 3
MULTIPOINT = 4
MULTILINESTRING = 5
MULTIPOLYGON = 6
GEOMETRYCOLLECTION = 7

ST_GEOMFROMGEOHASH (geohash[, precision])

Returns a POLYGON boundary box using the given geohash with a precision set by the integer precision. If precision is specified, the function will use as many characters in the hash equal to precision to create the geometry. If no precision is specified, the full length of the geohash is used.See Geohash for an example.

ST_GEOMFROMH3(h3_index)

Alias for H3_CELLTOBOUNDARY; see H3 Functions.

ST_GEOMFROMTEXT(wkt)

Returns a geometry from the given Well-Known text representation wkt. Note that this function is only compatible with constants.

ST_H3(wkt, resolution)

Alias for H3_GEOMTOCELL; see H3 Functions.

ST_HEXGRID (xmin, ymin, xmax, ymax, cell_side[, limit])

Creates a MULTIPOLYGON containing a grid of hexagons between given minimum and maximum points of a bounding box. The minimum point cannot be greater than or equal to the maximum point. The size (in meters) of the individual hexagons’ sides is determined by cell_side. The cell_side cannot be greater than the width or height of the bounding box. The maximum number of cells that can be produced is determined by limit, a positive integer. Supported values for limit:

-1 - No limit to the number of cells generated (effectively limited by system memory)
0 (default) - 100 million cells
<n> - Custom limit of n cells

If the custom limit request specifies more cells (based on the bounding box and the cell_side) than the system limit, a null is returned.

ST_INTERIORRINGN(geom, n)

Returns the n-th interior LINESTRING ring of the POLYGON geom. If geom is not a POLYGON or the given n is out of range, a null is returned. The index begins at 1

ST_INTERSECTION(geom1, geom2)

Returns the shared portion between given geometries geom1 and geom2

ST_INTERSECTS(geom1, geom2)

Returns 1 (true) if the given geometries, geom1 and geom2, intersect in 2-D

ST_ISCLOSED(geom)

Returns 1 (true) if the given geometry’s (geom) start and end points coincide

ST_ISCOLLECTION(geom)

Returns 1 (true) if geom is a collection, e.g., GEOMETRYCOLLECTION, MULTIPOINT, MULTILINESTRING, etc.

ST_ISEMPTY(geom)

Returns 1 (true) if geom is empty

ST_ISRING(geom)

Returns 1 (true) if LINESTRING geom is both closed (per ST_ISCLOSED) and “simple” (per ST_ISSIMPLE). Returns 0 if geom is not a LINESTRING

ST_ISSIMPLE(geom)

Returns 1 (true) if geom has no anomalous geometric points, e.g., self-intersection or self-tangency

ST_ISVALID(geom)

Returns 1 (true) if geom (typically a [MULTI]POLYGON) is well formed. A POLYGON is valid if its rings do not cross, and its boundary intersects only at POINTs (not along a line). The POLYGON must also not have dangling LINESTRINGs. A MULTIPOLYGON is valid if all of its elements are also valid, and the interior rings of those elements do not intersect. Each element’s boundaries may touch but only at POINTs (not along a line). ST_MAKEVALID(geom) can be used to help correct invalid geometries.

ST_ISVALIDREASON(geom)

Returns Valid Geometry if geom is well formed, according to ST_ISVALID(geom); otherwise, returns the reason geom is determined to be malformed. ST_MAKEVALID(geom) can be used to help correct invalid geometries.Example:

Function Call	`ST_ISVALIDREASON(‘POLYGON((-1 0, 1 0, 1 1, -1 -1))‘)`
Return	`Self-intersection[0 0]`

ST_LENGTH(geom[, solution])

Returns the length of the geometry if it is a LINESTRING or MULTILINESTRING. Returns 0 if another type of geometry, e.g., POINT, MULTIPOINT, etc. GEOMETRYCOLLECTIONs are also supported but the aforementioned type limitation still applies; the collection will be recursively searched for LINESTRINGs and MULTILINESTRINGs and the summation of all supported geometry types is returned (unsupported types are ignored). Solution types available:

0 (default) - 2D Euclidean length
1 - length on a sphere in meters
2 - length on a spheroid in meters

ST_LINEFROMMULTIPOINT(geom)

Creates a LINESTRING from geom if it is a MULTIPOINT. Returns null if geom is not a MULTIPOINT

ST_LINEINTERPOLATEPOINT(geom, frac)

Returns a POINT on the LINESTRING geom that is the frac fraction of the distance along the line. If geom is either empty or not a LINESTRING, null is returned

ST_LINELOCATEPOINT(linestring, point)

Returns the location of the closest point in the given linestring to the given point as a value between 0 and 1. The return value is a fraction of the total linestring length.

ST_LINEMERGE(geom)

Returns a LINESTRING or MULTILINESTRING from a given geom. If geom is a MULTILINESTRING comprising LINESTRINGs with shared endpoints, a contiguous LINESTRING is returned. If geom is a LINESTRING or a MULTILINESTRING comprising LINESTRINGS without shared endpoints, geom is returned If geom is an empty (MULTI)LINESTRING or a (MULTI)POINT or (MULTI)POLYGON, an empty GEOMETRYCOLLECTION is returned.

ST_LINESUBSTRING (geom, start_frac, end_frac)

Returns the fraction of a given geom LINESTRING from the point that is the start_frac fraction of the distance along the line to the point that is the end_frac fraction of the distance along the line.For example, given LINESTRING(1 1, 2 2, 3 3) a start_fraction of 0 and an end_fraction of 0.25 would yield the first quarter of the given LINESTRING, or LINESTRING(1 1, 1.5 1.5).Returns null in the following cases:

input geometry is (MULTI)POINT, MULTILINESTRING, or (MULTI)POLYGON
start_frac is greater than end_frac
start_frac or end_frac are not between 0 & 1, inclusive

ST_LONGESTLINE (geom1, geom2[, solution])

Returns the LINESTRING that represents the longest line of points between the two geometries. If multiple longest lines are found, only the first line found is returned. If geom1 or geom2 is empty, null is returned. Solution types available:

0 (default) - Euclidean; uses degrees to calculate the longest line
1 - Sphere; uses meters to calculate the longest line
2 - Spheroid; uses meters to calculate the longest line, more accurate than sphere but slower performance

ST_MAKEENVELOPE (xmin, ymin, xmax, ymax)

Creates a rectangular POLYGON from the given min and max parameters

ST_MAKELINE(geom[, geom2])

Creates a LINESTRING from geom if it is a MULTIPOINT. If geom is a POINT, there must be at least one other POINT to construct a LINESTRING. If geom is a LINESTRING, it must have at least two points. Returns null if geom is not a POINT, MULTIPOINT, or LINESTRING

This function can be rather costly in terms of performance

ST_MAKEPOINT(x, y)

Creates a POINT at the given coordinate

This function can be rather costly in terms of performance

ST_MAKEPOLYGON(geom)

Creates a POLYGON from geom. Inputs must be closed LINESTRINGs

This function can be rather costly in terms of performance

ST_MAKETRIANGLE2D (x1, y1, x2, y2, x3, y3)

Creates a closed 2-D POLYGON with three vertices

ST_MAKETRIANGLE3D (x1, y1, z1, x2, y2, z2, x3, y3, z3)

Creates a closed 3-D POLYGON with three vertices

ST_MAKEVALID(geom[, options])

Attempts to convert geom into a valid geometry when it is malformed, as determined by ST_ISVALID(geom). Returns geom if it is a valid geometry already. The method used to convert invalid geometries into valid ones can be specified in options as a space-separated string of x=y key/value pairs. The keys and corresponding values are as follows:

method - the algorithm used to convert invalid geometries into valid ones; either:
- linework (default) - build geometry from lines extracted from geom
- structure - build geometry from interior & exterior rings extracted from geom
keepcollapsed - if using the method of structure, whether to drop portions of the converted geometry that collapse to lower dimensions:
- true (default) - keep portions of geometry that collapse to lower dimensions
- false - don’t keep portions of geometry that collapse to lower dimensions

Example using default linework method:

Function Call	`ST_MAKEVALID(‘POLYGON((-1 0, 1 0, 1 1, -1 -1))‘)`
Return	`MULTIPOLYGON (((-1 -1, -1 0, 0 0, -1 -1)), ((1 0, 0 0, 1 1, 1 0)))`

Example using the structure method without dropping collapsible parts of the converted geometry:

Function Call	`ST_MAKEVALID(‘POLYGON((0 0, 0 0, 0 0, 0 0))’, ‘method=structure keepcollapsed=true’)`
Return	`POINT (0 0)`

Example using the structure method with dropping collapsible parts of the converted geometry:

Function Call	`ST_MAKEVALID(‘POLYGON((0 0, 0 0, 0 0, 0 0))’, ‘method=structure keepcollapsed=false’)`
Return	`POLYGON EMPTY`

ST_MAXDISTANCE (geom1, geom2[, solution])

Returns the maximum distance between the given geom1 and geom2 geometries using the specified solution type. If geom1 or geom2 is empty, null is returned. Solution types available:

0 (default) - returns maximum 2-D Euclidean distance
1 - Sphere; returns maximum distance in meters
2 - Spheroid; returns maximum distance in meters, more accurate than sphere but slower performance

ST_MAXX(geom)

Returns the maximum x coordinate of a bounding box for the given geom geometry. This function works for 2-D and 3-D geometries.

ST_MAXY(geom)

Returns the maximum y coordinate of a bounding box for the given geom geometry. This function works for 2-D and 3-D geometries.

ST_MAXZ(geom)

Returns the maximum z coordinate of a bounding box for the given geom geometry. This function works for 2-D and 3-D geometries.

ST_MINX(geom)

Returns the minimum x coordinate of a bounding box for the given geom geometry. This function works for 2-D and 3-D geometries.

ST_MINY(geom)

Returns the minimum y coordinate of a bounding box for the given geom geometry. This function works for 2-D and 3-D geometries.

ST_MINZ(geom)

Returns the minimum z coordinate of a bounding box for the given geom geometry. This function works for 2-D and 3-D geometries.

ST_MULTI(geom)

Returns geom as a MULTI- geometry, e.g., a POINT would return a MULTIPOINT.

ST_MULTIPLERINGBUFFERS (geom, distance[, outside])

Creates multiple buffers at specified distance around the given geom geometry. Multiple distances are specified as comma-separated values in an array, e.g., [10,20,30]. Valid values for outside are:

FULL - indicates that buffers will overlap or cover the given geom geometry. This is the default.
OUTSIDE_ONLY - indicates that buffers will be rings around the given geom geometry.

ST_NDIMS(geom)

Returns the number of dimensions in geom. For X,Y data, this will return 2; if a Z component is present, it will return 3.

ST_NEAR(geom1, geom2)

Returns the portion of geom2 that is closest to geom1. If geom2 is a singular geometry object (e.g., POINT, LINESTRING, POLYGON), geom2 will be returned. If geom2 a multi-geometry, e.g., MULTIPOINT, MULTILINESTRING, etc., the nearest singular geometry in geom2 will be returned.

ST_NORMALIZE(geom)

Returns geom in its normalized (canonical) form, which may rearrange the points in lexicographical order.

ST_NPOINTS(geom)

Returns the number of points (vertices) in geom.

ST_NRINGS(geom)

Returns the total number of rings (including interior rings) in geom. For non-polygonal geometries, it will return 0. For MULTIPOLYGONs, it will return the total number of rings across all components.

ST_NUMGEOMETRIES(geom)

If geom is a collection or MULTI- geometry, returns the number of geometries. If geom is a single geometry, returns 1.

ST_NUMINTERIORRINGS(geom)

Returns the number of interior rings if geom is a POLYGON. Returns null if geom is anything else.

ST_NUMPOINTS(geom)

Returns the number of points in the geom LINESTRING. Returns null if geom is not a LINESTRING.

ST_OVERLAPS(geom1, geom2)

Returns 1 (true) if given geometries geom1 and geom2 share space. If geom1 and/or geom2 are a GEOMETRYCOLLECTION, a 0 is returned regardless of if the two geometries overlap

ST_PARTITION(geom[, threshold])

Returns a MULTIPOLYGON representing the given geom partitioned into a number of POLYGONs with a maximum number of vertices equal to the given threshold. Minimum value for threshold is 10; default value is 10000. If geom is not a POLYGON or MULTIPOLYGON, geom is returned. If the number of vertices in geom is less than the threshold, geom is returned.

ST_PERIMETER(geom[, solution])

Returns the perimeter of the geometry if it is a POLYGON or MULTIPOLYGON. Returns 0 if another type of geometry, e.g., POINT, MULTIPOINT, LINESTRING, or MULTILINESTRING. GEOMETRYCOLLECTIONs are also supported but the aforementioned type limitation still applies; the collection will be recursively searched for POLYGONs and MULTIPOLYGONs and the summation of all supported geometry types is returned (unsupported types are ignored). Solution types available:

0 (default) - 2D Euclidean length
1 - length on a sphere in meters
2 - length on a spheroid in meters

ST_POINT(x, y)

Returns a POINT with the given x and y coordinates.

ST_POINTFROMGEOHASH (geohash[, precision])

Returns a POINT using the given geohash with a precision set by the integer precision. If precision is specified, the function will use as many characters in the hash equal to precision to create the geometry. If no precision is specified, the full length of the geohash is used.

The POINT returned represents the center of the bounding box of the geohash

ST_POINTGRID (xmin, ymin, xmax, ymax, cell_side[, limit])

Creates a MULTIPOLYGON containing a square-shaped grid of points between given minimum and maximum points of a bounding box. The minimum point cannot be greater than or equal to the maximum point. The distance between the points (in meters) is determined by cell_side. The cell_side cannot be greater than the width or height of the bounding box. The maximum number of cells that can be produced is determined by limit, a positive integer. Supported values for limit:

-1 - No limit to the number of cells generated (effectively limited by system memory)
0 (default) - 100 million cells
<n> - Custom limit of n cells

If the custom limit request specifies more cells (based on the bounding box and the cell_side) than the system limit, a null is returned.

ST_POINTN(geom, n)

Returns the n-th point in LINESTRING geom. Negative values are valid, but note that they are counted backwards from the end of geom. A null is returned if geom is not a LINESTRING.

ST_POINTS(geom)

Returns a MULTIPOINT containing all of the coordinates of geom.

ST_PROJECT(geom, distance, azimuth)

Returns a POINT projected from a start point geom along a geodesic calculated using distance and azimuth. If geom is not a POINT, null is returned.

ST_REMOVEPOINT(geom, offset)

Remove a point from LINESTRING geom using offset to skip over POINTs in the LINESTRING. The offset is 0-based.

ST_REMOVEREPEATEDPOINTS (geom, tolerance)

Removes points from geom if the point’s vertices are greater than or equal to the tolerance of the previous point in the geometry’s list. If geom is not a MULTIPOINT, MULTILINESTRING, or a MULTIPOLYGON, no points will be removed.

ST_REVERSE(geom)

Return the geometry with its coordinate order reversed.

ST_ROTATE(geom, radians[, wkt])

Rotates geom counter-clockwise by radians radians. Optionally, the rotation origin can be provided as a WKT POINT WKT POINT (wkt). If not provided, geom will be rotated around (0, 0).

ST_ROTATE(geom, radians[, x, y])

Rotates geom counter-clockwise by radians radians. Optionally, the rotation origin can be provided as a coordinate pair (x & y). If not provided, geom will be rotated around (0, 0).

ST_SCALE(geom, wkt)

Scales geom by multiplying its respective vertices by the corresponding x, y values in the given WKT POINT.

Function Call	`ST_SCALE(‘POLYGON((1 2, -2 1, -1 -2, 2 -1, 1 2))’, GEOMETRY(‘POINT(3 5)‘))`
Return	`POLYGON ((3 10, -6 5, -3 -10, 6 -5, 3 10))`

ST_SCALE(geom, x, y)

Scales geom by multiplying its respective vertices by the given x & y values.

Function Call	`ST_SCALE(‘POLYGON((1 2, -2 1, -1 -2, 2 -1, 1 2))’, 3, 5)`
Return	`POLYGON ((3 10, -6 5, -3 -10, 6 -5, 3 10))`

ST_SEGMENTIZE (geom, max_segment_size[, solution])

Returns the given geom, but segmentized n number of times depending on how the max_segment_size distance (in units based on the solution type) divides up the original geometry. The new geom is guaranteed to have segments that are smaller than the given max_segment_size. Note that POINTs are not able to be segmentized. Collection geometries (GEOMETRYCOLLECTION, MULTILINESTRING, MULTIPOINT, etc.) can be segmentized, but only the individual parts will be segmentized, not the collection as a whole. Solution types available:

0 - Euclidean; uses degrees to calculate distance
1 (default) - Sphere; uses meters to calculate distance

ST_SETPOINT(geom1, position, geom2)

Replace a point of LINESTRING geom1 with POINT geom2 at position (base 0). Negative values are valid, but note that they are counted backwards from the end of geom.

ST_SHAREDPATH(geom1, geom2)

Returns a collection containing paths shared by geom1 and geom2.

ST_SHORTESTLINE(geom1, geom2)

Returns the 2-D LINESTRING that represents the shortest line of points between the two geometries. If multiple shortest lines are found, only the first line found is returned. If geom1 or geom2 is empty, null is returned

ST_SIMPLIFY(geom, tolerance)

Returns a simplified version of the given geom using an algorithm to reduce the number of points comprising a given geometry while attempting to best retain the original shape. The given tolerance determines how much to simplify the geometry. The higher the tolerance, the more simplified the returned geometry. Some holes might be removed and some invalid polygons (e.g., self-intersecting, etc.) might be present in the returned geometry. Only (MULTI)LINESTRINGs and (MULTI)POLYGONs can be simplified, including those found within GEOMETRYCOLLECTIONs; any other geometry objects will be returned unsimplified.

The tolerance should be provided in the same units as the data. As a rule of thumb, a tolerance of 0.00001 would correspond to about one meter.

ST_SIMPLIFYPRESERVETOPOLOGY (geom, tolerance)

Returns a simplified version of the given geom using an algorithm to reduce the number of points comprising a given geometry while attempting to best retain the original shape. The given tolerance determines how much to simplify the geometry. The higher the tolerance, the more simplified the returned geometry. No holes will be removed and no invalid polygons (e.g., self-intersecting, etc.) will be present in the returned geometry. Only (MULTI)LINESTRINGs and (MULTI)POLYGONs can be simplified, including those found within GEOMETRYCOLLECTIONs; any other geometry objects will be returned unsimplified.

The tolerance should be provided in the same units as the data. As a rule of thumb, a tolerance of 0.00001 would correspond to about one meter.

ST_SNAP(geom1, geom2, tolerance)

Snaps geom1 to geom2 within the given tolerance. If the tolerance causes geom1 to not snap, the geometries will be returned unchanged.

ST_SPLIT(geom1, geom2)

Returns a collection of geometries resulting from the split between geom1 and geom2 geometries.

ST_SQUAREGRID (xmin, ymin, xmax, ymax, cell_side[, limit])

Creates a MULTIPOLYGON containing a grid of squares between given minimum and maximum points of a bounding box. The minimum point cannot be greater than or equal to the maximum point. The size (in meters) of the individual squares’ sides is determined by cell_side. The cell_side cannot be greater than the width or height of the bounding box. The maximum number of cells that can be produced is determined by limit, a positive integer. Supported values for limit:

-1 - No limit to the number of cells generated (effectively limited by system memory)
0 (default) - 100 million cells
<n> - Custom limit of n cells

If the custom limit request specifies more cells (based on the bounding box and the cell_side) than the system limit, a null is returned.

ST_STARTPOINT(geom)

Returns the first point of LINESTRING geom as a POINT. Returns null if geom is not a LINESTRING.

ST_SYMDIFFERENCE(geom1, geom2)

Returns a geometry that represents the portions of geom1 and geom2 geometries that do not intersect.

ST_TOUCHES(geom1, geom2)

Returns 1 (true) if the given geometries, geom1 and geom2, have at least one point in common but their interiors do not intersect. If geom1 and/or geom2 are a GEOMETRYCOLLECTION, a 0 is returned regardless of if the two geometries touch

ST_TRANSLATE (geom, deltax, deltay[, deltaz])

Translate geom by given offsets deltax and deltay. A z-coordinate offset can be applied using deltaz. intersect.

ST_TRIANGLEGRID (xmin, ymin, xmax, ymax, cell_side[, limit])

Creates a MULTIPOLYGON containing a grid of triangles between given minimum and maximum points of a bounding box. The minimum point cannot be greater than or equal to the maximum point. The size (in meters) of the individual triangles’ sides is determined by cell_side. The cell_side cannot be greater than the width or height of the bounding box. The maximum number of cells that can be produced is determined by limit, a positive integer. Supported values for limit:

-1 - No limit to the number of cells generated (effectively limited by system memory)
0 (default) - 100 million cells
<n> - Custom limit of n cells

If the custom limit request specifies more cells (based on the bounding box and the cell_side) than the system limit, a null is returned.

ST_UNION(geom1, geom2)

Returns a geometry that represents the point set union of the two given geometries, geom1 and geom2.

ST_UNIONCOLLECTION(geom)

Returns a geometry that represents the point set union of a single given geometry geom.

ST_UPDATE(geom1, geom2)

Returns a geometry that is geom1 geometry updated by geom2 geometry

ST_VORONOIPOLYGONS(geom[, tolerance])

Returns a GEOMETRYCOLLECTION containing Voronoi polygons (regions consisting of points closer to a vertex in geom than any other vertices in geom) calculated from the vertices in geom and the given tolerance. The tolerance determines the distance at which points will be considered the same. An empty GEOMETRYCOLLECTION is returned if geom is an empty geometry, a single POINT, or a LINESTRING or POLYGON composed of equivalent vertices (e.g., POLYGON((0 0, 0 0, 0 0, 0 0)), LINESTRING(0 0, 0 0)).If no tolerance is specified, no vertices will be considered the same; each will have its own polygon.The bounding box for the result POLYGONs extends past the four edges of the input geom bounding box by an amount that is the greater of the input bounding box’s height and width. For instance, an input geom with a 3 x 4 bounding box will result in Voronoi polygons filling a space that is 11 x 12.

ST_WITHIN(geom1, geom2)

Returns 1 (true) if the geom1 geometry is inside the geom2 geometry. Note that as long as at least one point is inside of geom2, geom1 is considered within geom2 even if the rest of the geom1 lies along the boundary of geom2

ST_WKBTOWKT(geom)

Returns the text form (WKT) of a geometry from the given byte form (WKB)

ST_WKTTOWKB(geom)

Returns the byte form (WKB) of a geometry from the given text form (WKT)

ST_X(geom)

Returns the X coordinate of the POINT geom; if the coordinate is not available, null is returned. geom must be a POINT.

ST_XMAX(geom)

Alias for ST_MAXX()

ST_XMIN(geom)

Alias for ST_MINX()

ST_Y(geom)

Returns the Y coordinate of the POINT geom; if the coordinate is not available, null is returned. geom must be a POINT.

ST_YMAX(geom)

Alias for ST_MAXY()

ST_YMIN(geom)

Alias for ST_MINY()

ST_ZMAX(geom)

Alias for ST_MAXZ()

ST_ZMIN(geom)

Alias for ST_MINZ()

Aggregation Functions

ST_AGGREGATE_COLLECT(geom)

Alias for ST_COLLECT_AGGREGATE()

ST_AGGREGATE_INTERSECTION(geom)

Alias for ST_INTERSECTION_AGGREGATE()

ST_COLLECT_AGGREGATE(geom)

Returns a GEOMETRYCOLLECTION comprising all geometries found in the geom set. Any MULTI* geometries will be divided into separate singular geometries, e.g., MULTIPOINT((0 0), (1 1)) would be divided into POINT(0 0) and POINT(1 1) in the results; the same is true for elements of a GEOMETRYCOLLECTION found in geom, where a GEOMETRYCOLLECTION within the provided geom set will also be parsed, effectively flattening it and adding the individual geometries to the resulting GEOMETRYCOLLECTION. Any empty geometries in geom are ignored even if they are part of a GEOMETRYCOLLECTION. Any duplicate WKTs will be retained.

ST_DISSOLVE(geom)

Dissolves all geometries within a given set into a single geometry. Note that the resulting single geometry can still be a group of noncontiguous geometries but represented as a single group, e.g., a GEOMETRYCOLLECTION. Best performance when used in conjunction with adjacent geometries.

ST_DISSOLVEOVERLAPPING(geom)

ST_INTERSECTION_AGGREGATE(geom)

Returns a POLYGON or MULTIPOLYGON comprising the shared portion between all geometries found in the geom set. Returns an empty GEOMETRYCOLLECTION if there is no shared portion between all geometries. Functionally equivalent to ST_INTERSECTION(ST_INTERSECTION(geom1, geom2), ... geomN).

ST_LINESTRINGFROMORDEREDPOINTS(x, y, t)

Returns a LINESTRING that represents a “track” of the given points (x, y) ordered by the given sort column t (e.g., a timestamp or sequence number). If any of the values in the specified columns are null, the null “point” will be left out of the resulting LINESTRING. If there’s only one non-null “point” in the source table, a POINT is returned. If there are no non-null “points” in the source table, a null is returned.

ST_LINESTRINGFROMORDEREDPOINTS3D(x, y, z, t)

Returns a LINESTRING that represents a “track” of the given 3D points (x, y, z) ordered by the given sort column t (e.g., a timestamp or sequence number). If any of the values in the specified columns are null, the null “point” will be left out of the resulting LINESTRING. If there’s only one non-null “point” in the source table, a POINT is returned. If there are no non-null “points” in the source table, a null is returned.

ST_POLYGONIZE(geom)

Returns a GEOMETRYCOLLECTION containing POLYGONs comprising the provided (MULTI)LINESTRING(s). (MULTI)POINT and (MULTI)POLYGON geometries are ignored when calculating the resulting GEOMETRYCOLLECTION. If a valid POLYGON cannot be constructed from the provided (MULTI)LINESTRING(s), an empty GEOMETRYCOLLECTION will be returned.

Track Functions

The following functions are available in both SQL and the native API.

ST_TRACKDURATION([unit,] t)

Returns the total time, in the given unit, spanned by timestamp values in column t. Grouping by track ID will return the duration per track.The duration can be returned in any of the following date/time units:

YEAR
MONTH
DAY
HOUR
MINUTE
SECOND
MILLISECOND

The default unit is MILLISECOND.

ST_TRACKLENGTH(lat, lon, t[, solution])

Returns the total length of the track whose position values are specified by lat & lon and whose ordering is determined by an ascending sort on the timestamp t. Length can be returned with any of the following solution types:

Type	Description
`0`	2D Euclidean length in degrees
`1`	(default) Length on a sphere in meters
`2`	Length on a spheroid in meters

ST_TRACK_DWITHIN

The ST_TRACK_DWITHIN table function finds tracks that are related, within spatial or temporal bounds (or both) to the given track(s). The track(s) to use as the filter criteria will be specified by the SEARCH_* parameters. The TRACK_* parameters specify the set of tracks to search through for a match.

This function is only available in SQL or in the native API via /execute/sql.

The basic form of the ST_TRACK_DWITHIN function follows.

ST_TRACK_DWITHIN Table Function Syntax

SELECT *
FROM TABLE
(
    ST_TRACK_DWITHIN
    (
        TRACK_TABLE => INPUT_TABLE(<table name | select statement>),
        TRACK_ID_COLUMN => < '<column name>' | <column position> >,
        TRACK_X_COLUMN => < '<column name>' | <column position> >,
        TRACK_Y_COLUMN => < '<column name>' | <column position> >,
        TRACK_ORDER_COLUMN => < '<column name>' | <column position> >,
        SEARCH_TABLE => INPUT_TABLE(<table name | select statement>),
        SEARCH_ID_COLUMN => < '<column name>' | <column position> >,
        SEARCH_X_COLUMN => < '<column name>' | <column position> >,
        SEARCH_Y_COLUMN => < '<column name>' | <column position> >,
        SEARCH_ORDER_COLUMN => < '<column name>' | <column position> >,
        [
            SEARCH_XY_DISTANCE => '<spatial distance with unit>',
            SPATIAL_SOLUTION_TYPE => <solution type>,
            SEARCH_TIME_DISTANCE => '<temporal distance with unit>'
        ]
    )
)

TRACK_TABLE

Name of the table to search for tracks matching the track(s) specified in the SEARCH_* data set.To perform a search on the flights table, pass the name of the table to INPUT_TABLE:

INPUT_TABLE(flights)

To perform a search on the result of a query, pass the query to INPUT_TABLE:

INPUT_TABLE
(
    SELECT * FROM flights_west
    UNION
    SELECT * FROM flights_east
)

TRACK_ID_COLUMN

Table to search track column, containing the unique identifier for the track to which each track point belongs.

TRACK_X_COLUMN

Table to search track column, containing the longitude value of each track point.

TRACK_Y_COLUMN

Table to search track column, containing the latitude value of each track point.

TRACK_ORDER_COLUMN

Table to search track column, by which the searched track points will be sorted in ascending order.

SEARCH_TABLE

Name of the search criteria track table, containing the track(s) to be used as the filter criteria when searching for matching tracks in the TRACK_* data set.To match tracks from the flights_of_interest table, pass the name of the table to INPUT_TABLE:

INPUT_TABLE(flights_of_interest)

To match tracks from the result of a query, pass the query to INPUT_TABLE:

INPUT_TABLE
(
    SELECT * FROM flights_of_interest_west
    UNION
    SELECT * FROM flights_of_interest_east
)

SEARCH_ID_COLUMN

Search criteria track column, containing the unique identifier for the track to which each track point belongs.

SEARCH_X_COLUMN

Search criteria track column, containing the longitude value of each track point.

SEARCH_Y_COLUMN

Search criteria track column, containing the latitude value of each track point.

SEARCH_ORDER_COLUMN

Search criteria track column, by which the filter track points will be sorted in ascending order.

SEARCH_XY_DISTANCE

The radius around the given tracks to search for matching tracks.

This parameter is not applicable when using a SPATIAL_SOLUTION_TYPE of 0.

Unit	Description
`f`	Feet
`ki`	Kilometers
`m`	(default) Meters
`mi`	Miles

SPATIAL_SOLUTION_TYPE

Spatial match solution type; any of the following:

Type	Description
`0`	(default) 2D Euclidean length in degrees
`1`	Length on a sphere, returned in units specified by `SEARCH_XY_DISTANCE`
`2`	Length on a spheroid, returned in units specified by `SEARCH_XY_DISTANCE`

SEARCH_TIME_DISTANCE

The maximum allowable time difference between a search criteria track’s point and a matched track’s points. The time can use any of the following suffices for units:

Unit	Description
`ms`	Milliseconds
`s`	(default) Seconds
`m`	Minutes
`h`	Hours
`d`	Days
`w`	Weeks
`months`	Months
`y`	Years

To see the matches between a set of flights and a given set of flights of interest:

ST_TRACK_DWITHIN Example

SELECT *
FROM TABLE
(
	ST_TRACK_DWITHIN
	(
		TRACK_TABLE => INPUT_TABLE(example_geospatial.flights),
		TRACK_ID_COLUMN => 'id',
		TRACK_X_COLUMN => 'lon',
		TRACK_Y_COLUMN => 'lat',
		TRACK_ORDER_COLUMN => 'flight_time',
		SEARCH_TABLE => INPUT_TABLE
						(
							SELECT id, lon, lat, flight_time
							FROM example_geospatial.flights_northwest
							UNION
							SELECT id, lon, lat, flight_time
							FROM example_geospatial.flights_northeast
						),
		SEARCH_ID_COLUMN => 1,
		SEARCH_X_COLUMN => 2,
		SEARCH_Y_COLUMN => 3,
		SEARCH_ORDER_COLUMN => 4,
		SEARCH_TIME_DISTANCE => '5m',
		SEARCH_XY_DISTANCE => '1km',
		SPATIAL_SOLUTION_TYPE => 1
	)
)

ST_TRACKINTERSECTS

The ST_TRACKINTERSECTS table function finds tracks pass through the given geofence(s). The geofence(s) use as the filter will be specified by the GEOFENCE_* parameters. The TRACK_* parameters specify the set of tracks to search through for any intersecting the geofence(s). The result will include a record for each intersecting track & geofence pair, with:

a LINESTRING representing the full track intersecting a geofence
a LINESTRING representing the geofence it intersected

This function is only available in SQL or in the native API via /execute/sql.

The basic form of the ST_TRACKINTERSECTS function follows.

ST_TRACKINTERSECTS Table Function Syntax

SELECT *
FROM TABLE
(
    ST_TRACKINTERSECTS
    (
        TRACK_TABLE => INPUT_TABLE(<table name | select statement>),
        TRACK_ID_COLUMN => < '<column name>' | <column position> >,
        TRACK_X_COLUMN => < '<column name>' | <column position> >,
        TRACK_Y_COLUMN => < '<column name>' | <column position> >,
        TRACK_ORDER_COLUMN => < '<column name>' | <column position> >,
        GEOFENCE_TABLE => INPUT_TABLE(<table name | select statement>),
        GEOFENCE_ID_COLUMN => < '<column name>' | <column position> >,
        GEOFENCE_WKT_COLUMN => < '<column name>' | <column position> >
    )
)

TRACK_TABLE

Name of the table to search for tracks intersecting the geofence(s) specified in the SEARCH_* data set.To perform a search on the flights table, pass the name of the table to INPUT_TABLE:

INPUT_TABLE(flights)

To perform a search on the result of a query, pass the query to INPUT_TABLE:

INPUT_TABLE
(
    SELECT * FROM flights_west
    UNION
    SELECT * FROM flights_east
)

TRACK_ID_COLUMN

Table to search track column, containing the unique identifier for the track to which each track point belongs.

TRACK_X_COLUMN

Table to search track column, containing the longitude value of each track point.

TRACK_Y_COLUMN

Table to search track column, containing the latitude value of each track point.

TRACK_ORDER_COLUMN

Table to search track column, by which the searched track points will be sorted in ascending order.

GEOFENCE_TABLE

Name of the geofence table, containing the WKT(s) to be used as the filter criteria when searching for intersecting tracks in the TRACK_* data set.To search for tracks intersecting the geofence(s) from the flight_area_of_interest table, pass the name of the geofence table to INPUT_TABLE:

INPUT_TABLE(flight_area_of_interest)

To search for tracks intersecting the geofence(s) from the result of a query, pass the query to INPUT_TABLE:

INPUT_TABLE
(
    SELECT * FROM flight_area_of_interest_west
    UNION
    SELECT * FROM flight_area_of_interest_east
)

GEOFENCE_ID_COLUMN

Geofence column, containing the unique identifier for the geofence.

GEOFENCE_WKT_COLUMN

Geofence column, containing the WKT bounds of the geofence.

To see the intersections between a set of flights and an area of interest:

ST_TRACKINTERSECTS Example

SELECT *
FROM TABLE
(
	ST_TRACKINTERSECTS
	(
		TRACK_TABLE =>         INPUT_TABLE(example_geospatial.flights),
		TRACK_ID_COLUMN =>     'id',
		TRACK_X_COLUMN =>      'lon',
		TRACK_Y_COLUMN =>      'lat',
		TRACK_ORDER_COLUMN =>  'flight_time',
		GEOFENCE_TABLE =>      INPUT_TABLE(example_geospatial.track_geofence),
		GEOFENCE_ID_COLUMN =>  'fence_name',
		GEOFENCE_WKT_COLUMN => 'fence_wkt'
	)
)
ORDER BY id, fence_name

H3 Functions

The functions below support various operations using the H3 geospatial indexing scheme.

H3_CELLTOBOUNDARY(h3_index)

Returns a POLYGON boundary box of the H3 index identified by the given h3_index.See Geohash-H3 for an example.

H3_CELLTOCENTERCHILD(h3_index, res)

Alias for H3_CELLTOFIRSTCHILD.

H3_CELLTOCHILDN(h3_index, res, i)

Returns the H3 index corresponding to the 0-based i th child at resolution res for the given h3_index. The value i should be less than the number of children returned from calling H3_CELLTOCHILDRENSIZE(h3_index, res).

H3_CELLTOCHILDPOS(h3_index, res)

Returns the position of the given h3_index within an ordered list of the children of the cell’s parent at resolution res. This is the inverse of H3_CHILDPOSTOCELL (H3_CELLTOCHILDN).

H3_CELLTOCHILDRENSIZE(h3_index, res)

Returns the number of child cells at resolution res for the given h3_index.

H3_CELLTOFIRSTCHILD(h3_index, res)

Returns the H3 index corresponding to the first child at resolution res for the given h3_index.This is equivalent to H3_CELLTOCHILDN(h3_index,res,0).

H3_CELLTOLASTCHILD(h3_index, res)

Returns the H3 index corresponding to the last child at resolution res for the given h3_index.This is equivalent to H3_CELLTOCHILDN(h3_index,res,H3_CELLTOCHILDRENSIZE(h3_index, res)-1).

H3_CELLTOPARENT(h3_index, res)

Returns the H3 index corresponding to the parent cell of the given h3_index at resolution res.

H3_CELLTOXY(h3_index)

Returns a WKT POINT corresponding to the centroid of the given h3_index.

H3_CHILDPOSTOCELL(i, h3_index, res)

Alias for H3_CELLTOCHILDN(h3_index, res, i).

H3_GEOMTOCELL(geom, res)

Returns the H3 index, similar to a geohash, for the cell containing the centroid of the geometry geom with the given resolution res. The higher the resolution, the more precise the index is. The resolution res must be an integer between 0 and 15.See Geohash-H3 for an example.

H3_GETRESOLUTION(h3_index)

Returns the resolution of the H3 index h3_index.

H3_GRIDDISK(h3_index, k)

Returns an array of H3 indexes within a given distance k from the provided H3 index h3_index.

H3_GRIDDISKN(h3_index, k, i)

Returns the i ^th H3 index within a given distance k from the provided H3 index h3_index. This function would typically be used in conjunction with H3_NUMGRIDDISK via iter-join. The value of i should be between 0 and the result of H3_NUMGRIDDISK(h3_index, k) - 1.

H3_GRIDRING(h3_index, k)

Returns an array of H3 indexes comprising a hollow ring at a distance k from the provided H3 index h3_index.

H3_H3TOSTRING(h3_index)

Returns the string representation of the H3 index h3_index.

This function is the inverse of H3_STRINGTOH3.

H3_ISVALID(h3_index)

Returns 1 (true) if the given H3 index h3_index is a valid H3 index value; otherwise returns 0 (false).

H3_LATLNGTOCELL (latitude, longitude, res)

Returns the H3 index, similar to a geohash, for the cell containing the latitude and longitude coordinate, with the given resolution res. The higher the resolution, the more precise the index is. The resolution res must be an integer between 0 and 15.Equivalent to H3_XYTOCELL(longitude, latitude, res).

H3_NUMGRIDDISK(h3_index, k)

Returns the number of cells at a distance of k from the provided H3 index h3_index. This function would typically be used in conjunction with H3_GRIDDISKN via iter-join.

H3_NUMPOLYGONTOCELLS(geom, res)

Returns the number of cells at the given resolution res that are within the given geometry geom. Only polygon geometries are supported. This function would typically be used in conjunction with H3_POLYGONTOCELLSN via iter-join.

H3_POLYGONTOCELLS(geom, res)

Returns an array of H3 indexes at the given resolution res that are within the given geometry geom. Only polygon geometries are supported.

H3_POLYGONTOCELLSN(geom, res, i)

Returns the i ^th H3 index at the given resolution res that is within the given geometry geom. Only polygon geometries are supported. This function would typically be used in conjunction with H3_NUMPOLYGONTOCELLS via iter-join. The value of i should be between 0 and the value returned from H3_NUMPOLYGONTOCELLS(geom, res) - 1.

H3_STRINGTOH3(h3_string)

Returns the H3 index corresponding to the string representation h3_string.

This function is the inverse of H3_H3TOSTRING.

H3_XYTOCELL(x, y, res)

Returns the H3 index, similar to a geohash, for the cell containing the x and y coordinate, with the given resolution res. The higher the resolution, the more precise the index is. The resolution res must be an integer between 0 and 15.Equivalent to H3_LATLNGTOCELL(y, x, res).See Geohash-H3 for an example.

​Enhanced Performance Scalar Functions

​Scalar Functions

​Aggregation Functions

​Track Functions

​ST_TRACK_DWITHIN

​ST_TRACKINTERSECTS

​H3 Functions

Enhanced Performance Scalar Functions

Scalar Functions

Aggregation Functions

Track Functions

ST_TRACK_DWITHIN

ST_TRACKINTERSECTS

H3 Functions