# h3

[H3](https://eng.uber.com/h3/) is Uber's Hexagonal Hierarchical Spatial Index. Full documentation of the project can be found at [h3geo](https://h3geo.org/docs). You can also learn more about H3 in the [Spatial Indexes section](https://docs.carto.com/data-and-analysis/analytics-toolbox-for-oracle/key-concepts/spatial-indexes#h3) of this documentation.

## Oracle output conventions <a href="#oracle-output-conventions" id="oracle-output-conventions"></a>

Array-returning H3 functions in Oracle are **pipelined** and return nested-table types — `H3_INDEX_ARRAY` for cell IDs, `H3_DISTANCE_ARRAY` for `(h3, distance)` pairs. Consume them with `TABLE(...)`:

{% code overflow="wrap" lineNumbers="true" %}

```sql
SELECT COLUMN_VALUE AS h3
FROM TABLE(carto.H3_TOCHILDREN('83390cfffffffff', 4));
```

{% endcode %}

`H3_COMPACT` and `H3_UNCOMPACT` accept the same `H3_INDEX_ARRAY` type as input — pass cell IDs with `carto.H3_INDEX_ARRAY('a', 'b', ...)` or by piping another nested-table result through `CAST(MULTISET(...) AS carto.H3_INDEX_ARRAY)`.

Boolean-style functions (`H3_ISVALID`, `H3_ISPENTAGON`) return `NUMBER` constrained to 1/0, since Oracle SQL has no `BOOLEAN`. Compare with `= 1` rather than using truthy predicates.

## H3\_BOUNDARY <a href="#h3_boundary" id="h3_boundary"></a>

```sql
H3_BOUNDARY(index)
```

**Description**

Returns a geometry representing the H3 cell. It will return `null` on error (invalid input).

**Input parameters**

* `index`: `VARCHAR2(16)` The H3 cell index as hexadecimal.

**Return type**

`SDO_GEOMETRY` (polygon, SRID 4326)

**Example**

{% code overflow="wrap" lineNumbers="true" %}

```sql
SELECT SDO_UTIL.TO_WKTGEOMETRY(carto.H3_BOUNDARY('84390cbffffffff'))
FROM DUAL;
-- POLYGON ((-3.5769274353957314 40.613438595935165, -3.85975632308016 40.525472355369885, ...
```

{% endcode %}

## H3\_CENTER <a href="#h3_center" id="h3_center"></a>

```sql
H3_CENTER(index)
```

**Description**

Returns the center of the H3 cell as a point geometry. It will return `null` on error (invalid input).

**Input parameters**

* `index`: `VARCHAR2(16)` The H3 cell index.

**Return type**

`SDO_GEOMETRY` (point, SRID 4326)

**Example**

{% code overflow="wrap" lineNumbers="true" %}

```sql
SELECT SDO_UTIL.TO_WKTGEOMETRY(carto.H3_CENTER('84390cbffffffff'))
FROM DUAL;
-- POINT (-3.6176032466282892 40.37254058216577)
```

{% endcode %}

## H3\_COMPACT <a href="#h3_compact" id="h3_compact"></a>

```sql
H3_COMPACT(indexArray)
```

**Description**

Returns a set of hexagons across multiple resolutions that represent the same area as the input set of hexagons.

**Input parameters**

* `indexArray`: `H3_INDEX_ARRAY` of H3 cell indices as hexadecimal.

**Return type**

`H3_INDEX_ARRAY` (pipelined; `TABLE OF VARCHAR2(16)`).

**Example**

{% code overflow="wrap" lineNumbers="true" %}

```sql
SELECT COLUMN_VALUE AS h3
FROM TABLE(carto.H3_COMPACT(carto.H3_INDEX_ARRAY(
    '85390ca3fffffff', '85390ca7fffffff', '85390cabfffffff',
    '85390caffffffff', '85390cb3fffffff', '85390cb7fffffff',
    '85390cbbfffffff'
)));
-- 84390cbffffffff
```

{% endcode %}

To pipe the output of another nested-table function into `H3_COMPACT`, cast it via `MULTISET`:

{% code overflow="wrap" lineNumbers="true" %}

```sql
SELECT COLUMN_VALUE AS h3
FROM TABLE(carto.H3_COMPACT(
    CAST(MULTISET(
        SELECT COLUMN_VALUE
        FROM TABLE(carto.H3_TOCHILDREN('84390cbffffffff', 5))
    ) AS carto.H3_INDEX_ARRAY)
));
-- 84390cbffffffff
```

{% endcode %}

## H3\_DISTANCE <a href="#h3_distance" id="h3_distance"></a>

```sql
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. The two cells must share the same resolution.

**Input parameters**

* `origin`: `VARCHAR2(16)` The H3 cell index as hexadecimal.
* `destination`: `VARCHAR2(16)` The H3 cell index as hexadecimal.

**Return type**

`NUMBER`

**Example**

{% code overflow="wrap" lineNumbers="true" %}

```sql
SELECT carto.H3_DISTANCE('84390c1ffffffff', '84390cbffffffff') FROM DUAL;
-- 1
```

{% endcode %}

{% hint style="info" %}
**tip**

If you want the distance in meters use [SDO\_GEOM.SDO\_DISTANCE](https://docs.oracle.com/en/database/oracle/oracle-database/23/spatl/SDO_GEOM-reference.html) between the cell boundaries ([H3\_BOUNDARY](#h3_boundary)) or their centroids ([H3\_CENTER](#h3_center)).
{% endhint %}

## H3\_FROMGEOGPOINT <a href="#h3_fromgeogpoint" id="h3_fromgeogpoint"></a>

```sql
H3_FROMGEOGPOINT(point, resolution)
```

**Description**

Returns the H3 cell index that the point belongs to in the requested `resolution`. It will return `null` on error (non-point geometry, resolution out of bounds, or non-WGS84 SRID).

The point must be a 2D `SDO_GEOMETRY` in **WGS84 (SRID 4326)**. The function does not auto-transform: a point with an explicit SRID other than 4326 returns `null`. A `null` SRID is accepted and treated as WGS84 (matching the convention used by `SDO_UTIL.FROM_WKTGEOMETRY`).

**Input parameters**

* `point`: `SDO_GEOMETRY` 2D point in WGS84.
* `resolution`: `NUMBER` between 0 and 15 with the [H3 resolution](https://h3geo.org/docs/core-library/restable).

**Return type**

`VARCHAR2(16)`

**Example**

{% code overflow="wrap" lineNumbers="true" %}

```sql
SELECT carto.H3_FROMGEOGPOINT(
    SDO_GEOMETRY(2001, 4326,
                 SDO_POINT_TYPE(-3.7038, 40.4168, NULL),
                 NULL, NULL),
    4
) FROM DUAL;
-- 84390cbffffffff
```

{% endcode %}

{% hint style="info" %}
**tip**

If you want the cells covered by a polygon see [H3\_POLYFILL](#h3_polyfill).
{% endhint %}

## H3\_FROMLONGLAT <a href="#h3_fromlonglat" id="h3_fromlonglat"></a>

```sql
H3_FROMLONGLAT(longitude, latitude, resolution)
```

**Description**

Returns the H3 cell index that the point belongs to in the required `resolution`. Inputs are interpreted as WGS84 (SRID 4326). Coordinates outside the valid range are normalized. Returns `null` on error (resolution out of bounds).

**Input parameters**

* `longitude`: `NUMBER` horizontal coordinate of the map.
* `latitude`: `NUMBER` vertical coordinate of the map.
* `resolution`: `NUMBER` between 0 and 15 with the [H3 resolution](https://h3geo.org/docs/core-library/restable).

**Return type**

`VARCHAR2(16)`

**Example**

{% code overflow="wrap" lineNumbers="true" %}

```sql
SELECT carto.H3_FROMLONGLAT(-3.7038, 40.4168, 4) FROM DUAL;
-- 84390cbffffffff
```

{% endcode %}

## H3\_HEXRING <a href="#h3_hexring" id="h3_hexring"></a>

```sql
H3_HEXRING(origin, size)
```

**Description**

Returns all cell indexes in a **hollow hexagonal ring** centered at the origin in no particular order. For `size = 0` returns just the origin. Returns no rows for invalid input or negative `size`.

**Input parameters**

* `origin`: `VARCHAR2(16)` H3 cell index of the origin.
* `size`: `NUMBER` size of the ring (distance from the origin).

**Return type**

`H3_INDEX_ARRAY` (pipelined; `TABLE OF VARCHAR2(16)`).

**Example**

{% code overflow="wrap" lineNumbers="true" %}

```sql
SELECT COLUMN_VALUE AS h3
FROM TABLE(carto.H3_HEXRING('84390cbffffffff', 1));
-- 84392b5ffffffff
-- 84390c9ffffffff
-- 84390c1ffffffff
-- 84390c3ffffffff
-- 84390ddffffffff
-- 84392b7ffffffff
```

{% endcode %}

## H3\_INT\_TOSTRING <a href="#h3_int_tostring" id="h3_int_tostring"></a>

```sql
H3_INT_TOSTRING(index)
```

**Description**

Converts the integer representation of the H3 index to the string representation.

**Input parameters**

* `index`: `NUMBER` The H3 cell index.

**Return type**

`VARCHAR2(16)`

**Example**

{% code overflow="wrap" lineNumbers="true" %}

```sql
SELECT carto.H3_INT_TOSTRING(595478781590765567) FROM DUAL;
-- 84390cbffffffff
```

{% endcode %}

## H3\_ISPENTAGON <a href="#h3_ispentagon" id="h3_ispentagon"></a>

```sql
H3_ISPENTAGON(index)
```

**Description**

Returns `1` if the given H3 index is a pentagon. Returns `0` otherwise, even on invalid input.

**Input parameters**

* `index`: `VARCHAR2(16)` The H3 cell index as hexadecimal.

**Return type**

`NUMBER` (1/0). Oracle has no SQL `BOOLEAN`; callers compare with `= 1`.

**Examples**

{% code overflow="wrap" lineNumbers="true" %}

```sql
SELECT carto.H3_ISPENTAGON('84390cbffffffff') FROM DUAL;
-- 0
```

{% endcode %}

{% code overflow="wrap" lineNumbers="true" %}

```sql
SELECT carto.H3_ISPENTAGON('8075fffffffffff') FROM DUAL;
-- 1
```

{% endcode %}

## H3\_ISVALID <a href="#h3_isvalid" id="h3_isvalid"></a>

```sql
H3_ISVALID(index)
```

**Description**

Returns `1` when the given index is valid, `0` otherwise.

**Input parameters**

* `index`: `VARCHAR2(16)` The H3 cell index as hexadecimal.

**Return type**

`NUMBER` (1/0). Oracle has no SQL `BOOLEAN`; callers compare with `= 1`.

**Examples**

{% code overflow="wrap" lineNumbers="true" %}

```sql
SELECT carto.H3_ISVALID('84390cbffffffff') FROM DUAL;
-- 1
```

{% endcode %}

{% code overflow="wrap" lineNumbers="true" %}

```sql
SELECT carto.H3_ISVALID('1') FROM DUAL;
-- 0
```

{% endcode %}

## H3\_KRING <a href="#h3_kring" id="h3_kring"></a>

```sql
H3_KRING(origin, size)
```

**Description**

Returns all cell indexes in a **filled hexagonal k-ring** centered at the origin in no particular order. Returns no rows for invalid input or negative `size`.

**Input parameters**

* `origin`: `VARCHAR2(16)` H3 cell index of the origin.
* `size`: `NUMBER` size of the ring (distance from the origin).

**Return type**

`H3_INDEX_ARRAY` (pipelined; `TABLE OF VARCHAR2(16)`).

**Example**

{% code overflow="wrap" lineNumbers="true" %}

```sql
SELECT COLUMN_VALUE AS h3
FROM TABLE(carto.H3_KRING('84390cbffffffff', 1));
-- 84390cbffffffff
-- 84390c9ffffffff
-- 84390c1ffffffff
-- 84390c3ffffffff
-- 84390ddffffffff
-- 84392b7ffffffff
-- 84392b5ffffffff
```

{% endcode %}

## H3\_KRING\_DISTANCES <a href="#h3_kring_distances" id="h3_kring_distances"></a>

```sql
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. Returns no rows for invalid input or negative `size`.

**Input parameters**

* `origin`: `VARCHAR2(16)` H3 cell index of the origin.
* `size`: `NUMBER` size of the ring (distance from the origin).

**Return type**

`H3_DISTANCE_ARRAY` (pipelined; `TABLE OF H3_DISTANCE_PAIR(h3 VARCHAR2(16), distance NUMBER)`). Project the named fields when consuming with `TABLE(...)`.

**Example**

{% code overflow="wrap" lineNumbers="true" %}

```sql
SELECT t.h3, t.distance
FROM TABLE(carto.H3_KRING_DISTANCES('84390cbffffffff', 1)) t;
-- H3               DISTANCE
-- 84390cbffffffff  0
-- 84390c9ffffffff  1
-- 84390c1ffffffff  1
-- 84390c3ffffffff  1
-- 84390ddffffffff  1
-- 84392b7ffffffff  1
-- 84392b5ffffffff  1
```

{% endcode %}

## H3\_POLYFILL <a href="#h3_polyfill" id="h3_polyfill"></a>

```sql
H3_POLYFILL(geom, resolution)
```

**Description**

Returns the H3 cell indexes whose centers are contained in the given polygon at the requested resolution (equivalent to `mode = 'center'` in other CARTO Analytics Toolbox implementations). The resulting H3 set does not fully cover the input geometry but is significantly faster than coverage-based modes.

For coverage modes (`center` and `intersects`) over an entire query, use the [H3\_POLYFILL\_TABLE](#h3_polyfill_table) procedure.

Returns no rows on error (invalid input, resolution out of bounds, or non-polygon geometry).

**Input parameters**

* `geom`: `SDO_GEOMETRY` **polygon** or **multipolygon** representing the shape to cover. **GeometryCollections** containing polygons or multipolygons are also allowed. Non-polygon geometries (`POINT`, `LINESTRING`, etc.) are silently ignored — no error is raised. Interpreted as WGS84 (EPSG:4326).
* `resolution`: `NUMBER` level of detail. The value must be between 0 and 15 ([H3 resolution table](https://h3geo.org/docs/core-library/restable)).

**Return type**

`H3_INDEX_ARRAY` (pipelined; `TABLE OF VARCHAR2(16)`).

**Examples**

Single-row polyfill:

{% code overflow="wrap" lineNumbers="true" %}

```sql
SELECT COLUMN_VALUE AS h3
FROM TABLE(carto.H3_POLYFILL(
    SDO_UTIL.FROM_WKTGEOMETRY(
        'POLYGON ((-3.71219873428345 40.413365349070865,'
        ' -3.7144088745117 40.40965661286395,'
        ' -3.70659828186035 40.409525904775634,'
        ' -3.71219873428345 40.413365349070865))'
    ),
    9
));
-- 89390cb1b4bffff
```

{% endcode %}

Polyfill applied across a table of geometries (lateral join via comma + `TABLE(...)`):

{% code overflow="wrap" lineNumbers="true" %}

```sql
SELECT t.h3
  FROM <my-schema>.<my-table> g,
       TABLE(carto.H3_POLYFILL(g.geom, 9)) t;
```

{% endcode %}

## H3\_POLYFILL\_MODE <a href="#h3_polyfill_mode" id="h3_polyfill_mode"></a>

```sql
H3_POLYFILL_MODE(geom, resolution, polyfill_mode)
```

**Description**

Returns the H3 cell indexes contained in the given polygon at a requested resolution. Containment is determined by `polyfill_mode`: `center`, `intersects`, or `contains`.

* `center`: keeps the H3 cells whose centers fall inside the input polygon. Faster, does not fully cover the input. Equivalent to [`H3_POLYFILL`](#h3_polyfill).
* `intersects`: keeps the H3 cells whose boundaries intersect the input polygon. Fully covers the input.
* `contains`: keeps the H3 cells whose boundaries are fully inside the input polygon. Strictest mode.

**Input parameters**

* `geom`: `SDO_GEOMETRY` **polygon** or **multipolygon** representing the shape to cover. **GeometryCollections** containing polygons or multipolygons are also allowed. Non-polygon geometries (`POINT`, `LINESTRING`, etc.) are silently ignored — no error is raised. Interpreted as WGS84 (EPSG:4326).
* `resolution`: `NUMBER` H3 resolution between 0 and 15 ([H3 resolution table](https://h3geo.org/docs/core-library/restable)).
* `polyfill_mode`: `VARCHAR2` `'center'`, `'intersects'`, or `'contains'`. (Named `polyfill_mode` rather than `mode` because `mode` is a reserved word in Oracle PL/SQL.)

**Return type**

`H3_INDEX_ARRAY` (pipelined; `TABLE OF VARCHAR2(16)`).

NULL inputs, an out-of-range resolution, or an unknown mode produce no rows.

**Example**

{% code overflow="wrap" lineNumbers="true" %}

```sql
SELECT COLUMN_VALUE AS h3
FROM TABLE(carto.H3_POLYFILL_MODE(
    SDO_UTIL.FROM_WKTGEOMETRY(
        'POLYGON ((-3.71219873428345 40.413365349070865,'
        ' -3.7144088745117 40.40965661286395,'
        ' -3.70659828186035 40.409525904775634,'
        ' -3.71219873428345 40.413365349070865))'
    ),
    9,
    'intersects'
));
-- 89390ca3487ffff
-- 89390ca3497ffff
-- 89390ca34b3ffff
-- 89390cb1b4bffff
-- 89390cb1b4fffff
-- 89390cb1b5bffff
```

{% endcode %}

## H3\_POLYFILL\_TABLE <a href="#h3_polyfill_table" id="h3_polyfill_table"></a>

```sql
H3_POLYFILL_TABLE(input_query, resolution, polyfill_mode, output_table)
```

**Description**

Materializes the H3 polyfill of every row in `input_query` into a new table. The resulting table joins each input row with the polyfill cells of its `geom` column, preserving every other column the input query exposes.

This is the procedural form of [H3\_POLYFILL](#h3_polyfill) and supports three coverage modes:

* `center`: keeps the H3 cells whose centers fall inside the input polygon. Faster, does not fully cover the input.
* `intersects`: keeps the H3 cells whose boundaries intersect the input polygon. Fully covers the input.
* `contains`: keeps the H3 cells whose boundaries are fully inside the input polygon. Strictest mode.

Invalid `polyfill_mode`, `resolution` outside `0..15`, or `NULL` arguments cause the procedure to silently no-op (output table is not created).

**Input parameters**

* `input_query`: `VARCHAR2` SELECT statement; must expose a column named `geom` of type `SDO_GEOMETRY` (a **polygon** or **multipolygon**; non-polygon geometries are silently ignored). Any other columns are passed through to the output table.
* `resolution`: `NUMBER` H3 resolution between 0 and 15 ([H3 resolution table](https://h3geo.org/docs/core-library/restable)).
* `polyfill_mode`: `VARCHAR2` `'center'`, `'intersects'`, or `'contains'`. (Named `polyfill_mode` rather than `mode` because `mode` is a reserved word in Oracle PL/SQL.)
* `output_table`: `VARCHAR2` fully-qualified name of the table to create. Sanitized via `DBMS_ASSERT.QUALIFIED_SQL_NAME`.

**Return type**

None — creates the named table as a side effect. The output table has columns:

* `h3` `VARCHAR2(16)` — the polyfill cell.
* every other column produced by `input_query`.

**Example**

{% code overflow="wrap" lineNumbers="true" %}

```sql
BEGIN
    carto.H3_POLYFILL_TABLE(
        'SELECT SDO_UTIL.FROM_WKTGEOMETRY(''POLYGON ((-3.71219873428345 40.413365349070865, -3.7144088745117 40.40965661286395, -3.70659828186035 40.409525904775634, -3.71219873428345 40.413365349070865))'') AS geom FROM DUAL',
        9,
        'intersects',
        '<my-schema>.<my-output-table>'
    );
END;
/

SELECT h3 FROM <my-schema>.<my-output-table> ORDER BY h3;
-- 89390ca3487ffff
-- 89390ca3497ffff
-- 89390ca34b3ffff
-- 89390cb1b4bffff
-- 89390cb1b4fffff
-- 89390cb1b5bffff
```

{% endcode %}

## H3\_RESOLUTION <a href="#h3_resolution" id="h3_resolution"></a>

```sql
H3_RESOLUTION(index)
```

**Description**

Returns the resolution (0–15) of the given H3 cell. Returns `null` for invalid input.

**Input parameters**

* `index`: `VARCHAR2(16)` The H3 cell index as hexadecimal.

**Return type**

`NUMBER`

**Example**

{% code overflow="wrap" lineNumbers="true" %}

```sql
SELECT carto.H3_RESOLUTION('84390cbffffffff') FROM DUAL;
-- 4
```

{% endcode %}

## H3\_STRING\_TOINT <a href="#h3_string_toint" id="h3_string_toint"></a>

```sql
H3_STRING_TOINT(index)
```

**Description**

Converts the string representation of the H3 index to the integer representation.

**Input parameters**

* `index`: `VARCHAR2(16)` The H3 cell index.

**Return type**

`NUMBER`

**Example**

{% code overflow="wrap" lineNumbers="true" %}

```sql
SELECT carto.H3_STRING_TOINT('84390cbffffffff') FROM DUAL;
-- 595478781590765567
```

{% endcode %}

## H3\_TOCHILDREN <a href="#h3_tochildren" id="h3_tochildren"></a>

```sql
H3_TOCHILDREN(index, resolution)
```

**Description**

Returns the indexes of the children/descendents of the given hexagon at the given resolution. Returns no rows when the requested resolution is coarser than the input cell, or for invalid input.

**Input parameters**

* `index`: `VARCHAR2(16)` The H3 cell index as hexadecimal.
* `resolution`: `NUMBER` between 0 and 15 with the [H3 resolution](https://h3geo.org/docs/core-library/restable).

**Return type**

`H3_INDEX_ARRAY` (pipelined; `TABLE OF VARCHAR2(16)`).

**Example**

{% code overflow="wrap" lineNumbers="true" %}

```sql
SELECT COLUMN_VALUE AS h3
FROM TABLE(carto.H3_TOCHILDREN('83390cfffffffff', 4));
-- 84390c1ffffffff
-- 84390c3ffffffff
-- 84390c5ffffffff
-- 84390c7ffffffff
-- 84390c9ffffffff
-- 84390cbffffffff
-- 84390cdffffffff
```

{% endcode %}

## H3\_TOPARENT <a href="#h3_toparent" id="h3_toparent"></a>

```sql
H3_TOPARENT(index, resolution)
```

**Description**

Returns the H3 cell index of the parent of the given hexagon at the given resolution. Returns `null` if the requested resolution is not strictly coarser than the cell's resolution, or for invalid input.

**Input parameters**

* `index`: `VARCHAR2(16)` The H3 cell index as hexadecimal.
* `resolution`: `NUMBER` between 0 and 15 with the [H3 resolution](https://h3geo.org/docs/core-library/restable).

**Return type**

`VARCHAR2(16)`

**Example**

{% code overflow="wrap" lineNumbers="true" %}

```sql
SELECT carto.H3_TOPARENT('84390cbffffffff', 3) FROM DUAL;
-- 83390cfffffffff
```

{% endcode %}

## H3\_UNCOMPACT <a href="#h3_uncompact" id="h3_uncompact"></a>

```sql
H3_UNCOMPACT(indexArray, resolution)
```

**Description**

Returns the cells of `indexArray` expanded to the requested target `resolution`, representing the same area as the [compacted](#h3_compact) input. Cells already at the target resolution pass through unchanged; coarser cells are expanded to their descendants; cells finer than the target are skipped.

**Input parameters**

* `indexArray`: `H3_INDEX_ARRAY` of H3 cell indices as hexadecimal.
* `resolution`: `NUMBER` between 0 and 15 with the [H3 resolution](https://h3geo.org/docs/core-library/restable).

**Return type**

`H3_INDEX_ARRAY` (pipelined; `TABLE OF VARCHAR2(16)`).

**Example**

{% code overflow="wrap" lineNumbers="true" %}

```sql
SELECT COLUMN_VALUE AS h3
FROM TABLE(carto.H3_UNCOMPACT(
    carto.H3_INDEX_ARRAY('84390cbffffffff'), 5
));
-- 85390ca3fffffff
-- 85390ca7fffffff
-- 85390cabfffffff
-- 85390caffffffff
-- 85390cb3fffffff
-- 85390cb7fffffff
-- 85390cbbfffffff
```

{% endcode %}


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://docs.carto.com/data-and-analysis/analytics-toolbox-for-oracle/sql-reference/h3.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.