druid/docs/development/geo.md

103 lines
3.0 KiB
Markdown

---
id: geo
title: "Spatial filters"
---
<!--
~ Licensed to the Apache Software Foundation (ASF) under one
~ or more contributor license agreements. See the NOTICE file
~ distributed with this work for additional information
~ regarding copyright ownership. The ASF licenses this file
~ to you under the Apache License, Version 2.0 (the
~ "License"); you may not use this file except in compliance
~ with the License. You may obtain a copy of the License at
~
~ http://www.apache.org/licenses/LICENSE-2.0
~
~ Unless required by applicable law or agreed to in writing,
~ software distributed under the License is distributed on an
~ "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
~ KIND, either express or implied. See the License for the
~ specific language governing permissions and limitations
~ under the License.
-->
> Apache Druid supports two query languages: [Druid SQL](../querying/sql.md) and [native queries](../querying/querying.md).
> This document describes functionality that is only available in the native language.
Apache Druid supports filtering specially spatially indexed columns based on an origin and a bound.
## Spatial indexing
In any of the data specs, there is the option of providing spatial dimensions. For example, for a JSON data spec, spatial dimensions can be specified as follows:
```json
{
"type": "hadoop",
"dataSchema": {
"dataSource": "DatasourceName",
"parser": {
"type": "string",
"parseSpec": {
"format": "json",
"timestampSpec": {
"column": "timestamp",
"format": "auto"
},
"dimensionsSpec": {
"dimensions": [],
"spatialDimensions": [{
"dimName": "coordinates",
"dims": ["lat", "long"]
}]
}
}
}
}
}
```
## Spatial filters
|property|description|required?|
|--------|-----------|---------|
|dimName|The name of the spatial dimension. A spatial dimension may be constructed from multiple other dimensions or it may already exist as part of an event. If a spatial dimension already exists, it must be an array of coordinate values.|yes|
|dims|A list of dimension names that comprise a spatial dimension.|no|
The grammar for a spatial filter is as follows:
```json
"filter" : {
"type": "spatial",
"dimension": "spatialDim",
"bound": {
"type": "rectangular",
"minCoords": [10.0, 20.0],
"maxCoords": [30.0, 40.0]
}
}
```
### Bound types
#### `rectangular`
|property|description|required?|
|--------|-----------|---------|
|minCoords|List of minimum dimension coordinates for coordinates [x, y, z, …]|yes|
|maxCoords|List of maximum dimension coordinates for coordinates [x, y, z, …]|yes|
#### `radius`
|property|description|required?|
|--------|-----------|---------|
|coords|Origin coordinates in the form [x, y, z, …]|yes|
|radius|The float radius value|yes|
#### `polygon`
|property|description|required?|
|--------|-----------|---------|
|abscissa|Horizontal coordinate for corners of the polygon|yes|
|ordinate|Vertical coordinate for corners of the polygon|yes|