h3

CORE
​H3 is Uber’s Hexagonal Hierarchical Spatial Index. Full documentation of the project can be found at h3geo. You can also learn more about H3 in the Spatial Indexes section of this documentation.
H3_BOUNDARY
H3_BOUNDARY(index)
Description
Returns a geography representing the H3 cell. It will return null on error (invalid input).
index: STRING The H3 cell index.
Return type
GEOGRAPHY
Example
carto-un
carto-un-eu
carto-os
manual
SELECT `carto-un`.carto.H3_BOUNDARY('847b59dffffffff');
-- POLYGON((40.4650636223452 -3.9352772457965, 40.5465406026705 ...
SELECT `carto-un-eu`.carto.H3_BOUNDARY('847b59dffffffff');
-- POLYGON((40.4650636223452 -3.9352772457965, 40.5465406026705 ...
SELECT `carto-os`.carto.H3_BOUNDARY('847b59dffffffff');
-- POLYGON((40.4650636223452 -3.9352772457965, 40.5465406026705 ...
SELECT carto.H3_BOUNDARY('847b59dffffffff');
-- POLYGON((40.4650636223452 -3.9352772457965, 40.5465406026705 ...
Additional examples
​An H3 grid of Starbucks locations and simple cannibalization analysis​
H3_CENTER
H3_CENTER(index)
Description
Returns the center of the H3 cell as a GEOGRAPHY point. It will return null on error (invalid input).
index: STRING The H3 cell index.
Return type
GEOGRAPHY
Example
carto-un
carto-un-eu
carto-os
manual
SELECT `carto-un`.carto.H3_CENTER('847b59dffffffff');
-- POINT(40.3054764231743 -3.74320332556168)
SELECT `carto-un-eu`.carto.H3_CENTER('847b59dffffffff');
-- POINT(40.3054764231743 -3.74320332556168)
SELECT `carto-os`.carto.H3_CENTER('847b59dffffffff');
-- POINT(40.3054764231743 -3.74320332556168)
SELECT carto.H3_CENTER('847b59dffffffff');
-- POINT(40.3054764231743 -3.74320332556168)
H3_COMPACT
H3_COMPACT(indexArray)
Description
Returns an array with the indexes of a set of hexagons across multiple resolutions that represent the same area as the input set of hexagons.
indexArray: ARRAY<STRING> of H3 cell indices of the same resolution.
Return type
ARRAY<STRING>
Example
carto-un
carto-un-eu
carto-os
manual
SELECT `carto-un`.carto.H3_COMPACT(['857b59c3fffffff', '857b59c7fffffff', '857b59cbfffffff', '857b59cffffffff', '857b59d3fffffff', '857b59d7fffffff', '857b59dbfffffff']);
-- 847b59dffffffff
SELECT `carto-un-eu`.carto.H3_COMPACT(['857b59c3fffffff', '857b59c7fffffff', '857b59cbfffffff', '857b59cffffffff', '857b59d3fffffff', '857b59d7fffffff', '857b59dbfffffff']);
-- 847b59dffffffff
SELECT `carto-os`.carto.H3_COMPACT(['857b59c3fffffff', '857b59c7fffffff', '857b59cbfffffff', '857b59cffffffff', '857b59d3fffffff', '857b59d7fffffff', '857b59dbfffffff']);
-- 847b59dffffffff
SELECT carto.H3_COMPACT(['857b59c3fffffff', '857b59c7fffffff', '857b59cbfffffff', '857b59cffffffff', '857b59d3fffffff', '857b59d7fffffff', '857b59dbfffffff']);
-- 847b59dffffffff
H3_DISTANCE
H3_DISTANCE(origin, destination)
Description
Returns the grid distance between two hexagon indexes. This function may fail to find the distance between two indexes if they are very far apart or on opposite sides of a pentagon. Returns null on failure or invalid input.
origin: STRING origin H3 cell index.
destination: STRING destination H3 cell index.
Return type
INT64
Example
carto-un
carto-un-eu
carto-os
manual
SELECT `carto-un`.carto.H3_DISTANCE('847b591ffffffff', '847b59bffffffff');
-- 1
SELECT `carto-un-eu`.carto.H3_DISTANCE('847b591ffffffff', '847b59bffffffff');
-- 1
SELECT `carto-os`.carto.H3_DISTANCE('847b591ffffffff', '847b59bffffffff');
-- 1
SELECT carto.H3_DISTANCE('847b591ffffffff', '847b59bffffffff');
-- 1
tip
If you want the distance in meters use ST_DISTANCE between the cells (H3_BOUNDARY) or their centroid.
Additional examples
​Opening a new Pizza Hut location in Honolulu​
H3_FROMGEOGPOINT
H3_FROMGEOGPOINT(point, resolution)
Description
Returns the H3 cell index that the point belongs to in the required resolution. It will return null on error (invalid geography type or resolution out of bounds).
point: GEOGRAPHY point to get the H3 cell from.
resolution: INT64 number between 0 and 15 with the H3 resolution.
Return type
STRING
Example
carto-un
carto-un-eu
carto-os
manual
SELECT `carto-un`.carto.H3_FROMGEOGPOINT(ST_GEOGPOINT(40.4168, -3.7038), 4);
-- 847b59dffffffff
SELECT `carto-un-eu`.carto.H3_FROMGEOGPOINT(ST_GEOGPOINT(40.4168, -3.7038), 4);
-- 847b59dffffffff
SELECT `carto-os`.carto.H3_FROMGEOGPOINT(ST_GEOGPOINT(40.4168, -3.7038), 4);
-- 847b59dffffffff
SELECT carto.H3_FROMGEOGPOINT(ST_GEOGPOINT(40.4168, -3.7038), 4);
-- 847b59dffffffff
tip
If you want the cells covered by a POLYGON see H3_POLYFILL.
Additional examples
​An H3 grid of Starbucks locations and simple cannibalization analysis​
H3_FROMLONGLAT
H3_FROMLONGLAT(longitude, latitude, resolution)
Description
Returns the H3 cell index that the point belongs to in the required resolution. It will return null on error (resolution out of bounds).
longitude: FLOAT64 horizontal coordinate of the map.
latitude: FLOAT64 vertical coordinate of the map.
resolution: INT64 number between 0 and 15 with the H3 resolution.
Return type
STRING
Example
carto-un
carto-un-eu
carto-os
manual
SELECT `carto-un`.carto.H3_FROMLONGLAT(40.4168, -3.7038, 4);
-- 847b59dffffffff
SELECT `carto-un-eu`.carto.H3_FROMLONGLAT(40.4168, -3.7038, 4);
-- 847b59dffffffff
SELECT `carto-os`.carto.H3_FROMLONGLAT(40.4168, -3.7038, 4);
-- 847b59dffffffff
SELECT carto.H3_FROMLONGLAT(40.4168, -3.7038, 4);
-- 847b59dffffffff
H3_HEXRING
H3_HEXRING(origin, size)
Description
Returns all cell indexes in a hollow hexagonal ring centered at the origin in no particular order. Unlike H3_KRING, this function will throw an exception if there is a pentagon anywhere in the ring.
origin: STRING H3 cell index of the origin.
size: INT64 size of the ring (distance from the origin).
Return type
ARRAY<STRING>
Example
carto-un
carto-un-eu
carto-os
manual
SELECT `carto-un`.carto.H3_HEXRING('837b59fffffffff', 1);
-- 837b5dfffffffff
-- 837b58fffffffff
-- 837b5bfffffffff
-- 837a66fffffffff
-- 837a64fffffffff
-- 837b4afffffffff
SELECT `carto-un-eu`.carto.H3_HEXRING('837b59fffffffff', 1);
-- 837b5dfffffffff
-- 837b58fffffffff
-- 837b5bfffffffff
-- 837a66fffffffff
-- 837a64fffffffff
-- 837b4afffffffff
SELECT `carto-os`.carto.H3_HEXRING('837b59fffffffff', 1);
-- 837b5dfffffffff
-- 837b58fffffffff
-- 837b5bfffffffff
-- 837a66fffffffff
-- 837a64fffffffff
-- 837b4afffffffff
SELECT carto.H3_HEXRING('837b59fffffffff', 1);
-- 837b5dfffffffff
-- 837b58fffffffff
-- 837b5bfffffffff
-- 837a66fffffffff
-- 837a64fffffffff
-- 837b4afffffffff
H3_INT_TOSTRING
H3_INT_TOSTRING(index)
Description
Converts the integer representation of the H3 index to the string representation.
index: INT64 The H3 cell index.
Return type
STRING
Example
carto-un
carto-un-eu
carto-os
manual
SELECT `carto-un`.carto.H3_INT_TOSTRING(596645165859340287);
-- 847b59dffffffff
SELECT `carto-un-eu`.carto.H3_INT_TOSTRING(596645165859340287);
-- 847b59dffffffff
SELECT `carto-os`.carto.H3_INT_TOSTRING(596645165859340287);
-- 847b59dffffffff
SELECT carto.H3_INT_TOSTRING(596645165859340287);
-- 847b59dffffffff
H3_ISPENTAGON
H3_ISPENTAGON(index)
Description
Returns true if given H3 index is a pentagon. Returns false otherwise, even on invalid input.
index: STRING The H3 cell index.
Return type
BOOLEAN
Example
carto-un
carto-un-eu
carto-os
manual
SELECT `carto-un`.carto.H3_ISPENTAGON('837b59fffffffff');
-- false
SELECT `carto-un-eu`.carto.H3_ISPENTAGON('837b59fffffffff');
-- false
SELECT `carto-os`.carto.H3_ISPENTAGON('837b59fffffffff');
-- false
SELECT carto.H3_ISPENTAGON('837b59fffffffff');
-- false
carto-un
carto-un-eu
carto-os
manual
SELECT `carto-un`.carto.H3_ISPENTAGON('8075fffffffffff');
-- true
SELECT `carto-un-eu`.carto.H3_ISPENTAGON('8075fffffffffff');
-- true
SELECT `carto-os`.carto.H3_ISPENTAGON('8075fffffffffff');
-- true
SELECT carto.H3_ISPENTAGON('8075fffffffffff');
-- true
H3_ISVALID
H3_ISVALID(index)
Description
Returns true when the given index is a valid H3 index, false otherwise.
index: STRING The H3 cell index.
Return type
BOOLEAN
Examples
carto-un
carto-un-eu
carto-os
manual
SELECT `carto-un`.carto.H3_ISVALID('847b59dffffffff');
-- true
SELECT `carto-un-eu`.carto.H3_ISVALID('847b59dffffffff');
-- true
SELECT `carto-os`.carto.H3_ISVALID('847b59dffffffff');
-- true
SELECT carto.H3_ISVALID('847b59dffffffff');
-- true
carto-un
carto-un-eu
carto-os
manual
SELECT `carto-un`.carto.H3_ISVALID('1');
-- false
SELECT `carto-un-eu`.carto.H3_ISVALID('1');
-- false
SELECT `carto-os`.carto.H3_ISVALID('1');
-- false
SELECT carto.H3_ISVALID('1');
-- false
H3_KRING
H3_KRING(origin, size)
Description
Returns all cell indexes in a filled hexagonal k-ring centered at the origin in no particular order.
origin: STRING H3 cell index of the origin.
size: INT64 size of the ring (distance from the origin).
Return type
ARRAY<STRING>
Example
carto-un
carto-un-eu
carto-os
manual
SELECT `carto-un`.carto.H3_KRING('837b59fffffffff', 1);
-- 837b59fffffffff
-- 837b58fffffffff
-- 837b5bfffffffff
-- 837a66fffffffff
-- 837a64fffffffff
-- 837b4afffffffff
-- 837b5dfffffffff
SELECT `carto-un-eu`.carto.H3_KRING('837b59fffffffff', 1);
-- 837b59fffffffff
-- 837b58fffffffff
-- 837b5bfffffffff
-- 837a66fffffffff
-- 837a64fffffffff
-- 837b4afffffffff
-- 837b5dfffffffff
SELECT `carto-os`.carto.H3_KRING('837b59fffffffff', 1);
-- 837b59fffffffff
-- 837b58fffffffff
-- 837b5bfffffffff
-- 837a66fffffffff
-- 837a64fffffffff
-- 837b4afffffffff
-- 837b5dfffffffff
SELECT carto.H3_KRING('837b59fffffffff', 1);
-- 837b59fffffffff
-- 837b58fffffffff
-- 837b5bfffffffff
-- 837a66fffffffff
-- 837a64fffffffff
-- 837b4afffffffff
-- 837b5dfffffffff
Additional examples
​An H3 grid of Starbucks locations and simple cannibalization analysis​
H3_KRING_DISTANCES
H3_KRING_DISTANCES(origin, size)
Description
Returns all cell indexes and their distances in a filled hexagonal k-ring centered at the origin in no particular order.
origin: STRING H3 cell index of the origin.
size: INT64 size of the ring (distance from the origin).
Return type
ARRAY<STRUCT<index STRING, distance INT64>>
Example
carto-un
carto-un-eu
carto-os
manual
SELECT `carto-un`.carto.H3_KRING_DISTANCES('837b59fffffffff', 1);
-- {"index": "837b59fffffffff", "distance": "0"}
-- {"index": "837b5dfffffffff", "distance": "1"}
-- {"index": "837b58fffffffff", "distance": "1"}
-- {"index": "837b5bfffffffff", "distance": "1"}
-- {"index": "837a66fffffffff", "distance": "1"}
-- {"index": "837a64fffffffff", "distance": "1"}
-- {"index": "837b4afffffffff", "distance": "1"}
SELECT `carto-un-eu`.carto.H3_KRING_DISTANCES('837b59fffffffff', 1);
-- {"index": "837b59fffffffff", "distance": "0"}
-- {"index": "837b5dfffffffff", "distance": "1"}
-- {"index": "837b58fffffffff", "distance": "1"}
-- {"index": "837b5bfffffffff", "distance": "1"}
-- {"index": "837a66fffffffff", "distance": "1"}
-- {"index": "837a64fffffffff", "distance": "1"}
-- {"index": "837b4afffffffff", "distance": "1"}
SELECT `carto-os`.carto.H3_KRING_DISTANCES('837b59fffffffff', 1);
-- {"index": "837b59fffffffff", "distance": "0"}
-- {"index": "837b5dfffffffff", "distance": "1"}
-- {"index": "837b58fffffffff", "distance": "1"}
-- {"index": "837b5bfffffffff", "distance": "1"}
-- {"index": "837a66fffffffff", "distance": "1"}
-- {"index": "837a64fffffffff", "distance": "1"}
-- {"index": "837b4afffffffff", "distance": "1"}
SELECT carto.H3_KRING_DISTANCES('837b59fffffffff', 1);
-- {"index": "837b59fffffffff", "distance": "0"}
-- {"index": "837b5dfffffffff", "distance": "1"}
-- {"index": "837b58fffffffff", "distance": "1"}
-- {"index": "837b5bfffffffff", "distance": "1"}
-- {"index": "837a66fffffffff", "distance": "1"}
-- {"index": "837a64fffffffff", "distance": "1"}
-- {"index": "837b4afffffffff", "distance": "1"}
H3_POLYFILL
H3_POLYFILL(geography, resolution)
Description
Returns an array with all the H3 cell indexes with centers contained in a given polygon. It will return null on error (invalid geography type or resolution out of bounds). In case of lines, it will return the H3 cell indexes intersecting those lines. For a given point, it will return the H3 index of cell in which that point is contained.
warning
Lines polyfill is calculated by approximating S2 cells to H3 cells, in some cases some cells might be missing.
geography: GEOGRAPHY representing the area to cover.
resolution: INT64 number between 0 and 15 with the H3 resolution.
Return type
ARRAY<STRING>
Example
carto-un
carto-un-eu
carto-os
manual
SELECT `carto-un`.carto.H3_POLYFILL(
    ST_GEOGFROMTEXT('POLYGON ((30 10, 40 40, 20 40, 10 20, 30 10))'), 4);
-- 846b26bffffffff
-- 843e8b1ffffffff
-- 842d1e5ffffffff
-- 843ece5ffffffff
-- ...
SELECT `carto-un-eu`.carto.H3_POLYFILL(
    ST_GEOGFROMTEXT('POLYGON ((30 10, 40 40, 20 40, 10 20, 30 10))'), 4);
-- 846b26bffffffff
-- 843e8b1ffffffff
-- 842d1e5ffffffff
-- 843ece5ffffffff
-- ...
SELECT `carto-os`.carto.H3_POLYFILL(
    ST_GEOGFROMTEXT('POLYGON ((30 10, 40 40, 20 40, 10 20, 30 10))'), 4);
-- 846b26bffffffff
-- 843e8b1ffffffff
-- 842d1e5ffffffff
-- 843ece5ffffffff
-- ...
SELECT carto.H3_POLYFILL(
    ST_GEOGFROMTEXT('POLYGON ((30 10, 40 40, 20 40, 10 20, 30 10))'), 4);
-- 846b26bffffffff
-- 843e8b1ffffffff
-- 842d1e5ffffffff
-- 843ece5ffffffff
-- ...
Additional examples
​Opening a new Pizza Hut location in Honolulu​
H3_RESOLUTION
H3_RESOLUTION(index)
Description
Returns the H3 cell resolution as an integer. It will return null on error (invalid input).
index: STRING The H3 cell index.
Return type
INT64
Example
carto-un
carto-un-eu
carto-os
manual
SELECT `carto-un`.carto.H3_RESOLUTION('847b59dffffffff');
-- 4
SELECT `carto-un-eu`.carto.H3_RESOLUTION('847b59dffffffff');
-- 4
SELECT `carto-os`.carto.H3_RESOLUTION('847b59dffffffff');
-- 4
SELECT carto.H3_RESOLUTION('847b59dffffffff');
-- 4
H3_STRING_TOINT
H3_STRING_TOINT(index)
Description
Converts the string representation of the H3 index to the integer representation.
index: STRING The H3 cell index.
Return type
INT64
Example
carto-un
carto-un-eu
carto-os
manual
SELECT `carto-un`.carto.H3_STRING_TOINT('847b59dffffffff');
-- 596645165859340287
SELECT `carto-un-eu`.carto.H3_STRING_TOINT('847b59dffffffff');
-- 596645165859340287
SELECT `carto-os`.carto.H3_STRING_TOINT('847b59dffffffff');
-- 596645165859340287
SELECT carto.H3_STRING_TOINT('847b59dffffffff');
-- 596645165859340287
H3_TOCHILDREN
H3_TOCHILDREN(index, resolution)
Description
Returns an array with the H3 indexes of the children/descendents of the given hexagon at the given resolution.
index: STRING The H3 cell index.
resolution: INT64 number between 0 and 15 with the H3 resolution.
Return type
ARRAY<STRING>
Example
carto-un
carto-un-eu
carto-os
manual
SELECT `carto-un`.carto.H3_TOCHILDREN('837b59fffffffff', 4);
-- 847b591ffffffff
-- 847b593ffffffff
-- 847b595ffffffff
-- 847b597ffffffff
-- 847b599ffffffff
-- 847b59bffffffff
-- 847b59dffffffff
SELECT `carto-un-eu`.carto.H3_TOCHILDREN('837b59fffffffff', 4);
-- 847b591ffffffff
-- 847b593ffffffff
-- 847b595ffffffff
-- 847b597ffffffff
-- 847b599ffffffff
-- 847b59bffffffff
-- 847b59dffffffff
SELECT `carto-os`.carto.H3_TOCHILDREN('837b59fffffffff', 4);
-- 847b591ffffffff
-- 847b593ffffffff
-- 847b595ffffffff
-- 847b597ffffffff
-- 847b599ffffffff
-- 847b59bffffffff
-- 847b59dffffffff
SELECT carto.H3_TOCHILDREN('837b59fffffffff', 4);
-- 847b591ffffffff
-- 847b593ffffffff
-- 847b595ffffffff
-- 847b597ffffffff
-- 847b599ffffffff
-- 847b59bffffffff
-- 847b59dffffffff
H3_TOPARENT
H3_TOPARENT(index, resolution)
Description
Returns the H3 cell index of the parent of the given hexagon at the given resolution.
index: STRING The H3 cell index.
resolution: INT64 number between 0 and 15 with the H3 resolution.
Return type
STRING
Example
carto-un
carto-un-eu
carto-os
manual
SELECT `carto-un`.carto.H3_TOPARENT('847b59dffffffff', 3);
-- 837b59fffffffff
SELECT `carto-un-eu`.carto.H3_TOPARENT('847b59dffffffff', 3);
-- 837b59fffffffff
SELECT `carto-os`.carto.H3_TOPARENT('847b59dffffffff', 3);
-- 837b59fffffffff
SELECT carto.H3_TOPARENT('847b59dffffffff', 3);
-- 837b59fffffffff
H3_UNCOMPACT
H3_UNCOMPACT(indexArray, resolution)
Description
Returns an array with the H3 indexes of a set of hexagons of the same resolution that represent the same area as the compacted input hexagons.
indexArray: ARRAY<STRING> of H3 cell indices.
resolution: INT64 number between 0 and 15 with the H3 resolution.
Return type
ARRAY<STRING>
Example
carto-un