[[query-dsl-geo-bounding-box-query]]
=== Geo Bounding Box Query

A query allowing to filter hits based on a point location using a
bounding box. Assuming the following indexed document:

[source,js]
--------------------------------------------------
PUT /my_locations
{
    "mappings": {
        "_doc": {
            "properties": {
                "pin": {
                    "properties": {
                        "location": {
                            "type": "geo_point"
                        }
                    }
                }
            }
        }
    }
}

PUT /my_locations/_doc/1
{
    "pin" : {
        "location" : {
            "lat" : 40.12,
            "lon" : -71.34
        }
    }
}
--------------------------------------------------
// CONSOLE
// TESTSETUP

Then the following simple query can be executed with a
`geo_bounding_box` filter:

[source,js]
--------------------------------------------------
GET /_search
{
    "query": {
        "bool" : {
            "must" : {
                "match_all" : {}
            },
            "filter" : {
                "geo_bounding_box" : {
                    "pin.location" : {
                        "top_left" : {
                            "lat" : 40.73,
                            "lon" : -74.1
                        },
                        "bottom_right" : {
                            "lat" : 40.01,
                            "lon" : -71.12
                        }
                    }
                }
            }
        }
    }
}
--------------------------------------------------
// CONSOLE

[float]
==== Query Options

[cols="<,<",options="header",]
|=======================================================================
|Option |Description
|`_name` |Optional name field to identify the filter

|`validation_method` |Set to `IGNORE_MALFORMED` to
accept geo points with invalid latitude or longitude, set to
`COERCE` to also try to infer correct latitude or longitude. (default is `STRICT`).

|`type` |Set to one of `indexed` or `memory` to defines whether this filter will
be executed in memory or indexed. See <<geo-bbox-type,Type>> below for further details
Default is `memory`.
|=======================================================================

[float]
==== Accepted Formats

In much the same way the geo_point type can accept different
representations of the geo point, the filter can accept it as well:

[float]
===== Lat Lon As Properties

[source,js]
--------------------------------------------------
GET /_search
{
    "query": {
        "bool" : {
            "must" : {
                "match_all" : {}
            },
            "filter" : {
                "geo_bounding_box" : {
                    "pin.location" : {
                        "top_left" : {
                            "lat" : 40.73,
                            "lon" : -74.1
                        },
                        "bottom_right" : {
                            "lat" : 40.01,
                            "lon" : -71.12
                        }
                    }
                }
            }
        }
    }
}
--------------------------------------------------
// CONSOLE

[float]
===== Lat Lon As Array

Format in `[lon, lat]`, note, the order of lon/lat here in order to
conform with http://geojson.org/[GeoJSON].

[source,js]
--------------------------------------------------
GET /_search
{
    "query": {
        "bool" : {
            "must" : {
                "match_all" : {}
            },
            "filter" : {
                "geo_bounding_box" : {
                    "pin.location" : {
                        "top_left" : [-74.1, 40.73],
                        "bottom_right" : [-71.12, 40.01]
                    }
                }
            }
        }
    }
}
--------------------------------------------------
// CONSOLE

[float]
===== Lat Lon As String

Format in `lat,lon`.

[source,js]
--------------------------------------------------
GET /_search
{
    "query": {
        "bool" : {
            "must" : {
                "match_all" : {}
            },
            "filter" : {
                "geo_bounding_box" : {
                    "pin.location" : {
                        "top_left" : "40.73, -74.1",
                        "bottom_right" : "40.01, -71.12"
                    }
                }
            }
    }
}
}
--------------------------------------------------
// CONSOLE

[float]
===== Bounding Box as Well-Known Text (WKT)

[source,js]
--------------------------------------------------
GET /_search
{
    "query": {
        "bool" : {
            "must" : {
                "match_all" : {}
            },
            "filter" : {
                "geo_bounding_box" : {
                    "pin.location" : {
                        "wkt" : "BBOX (-74.1, -71.12, 40.73, 40.01)"
                    }
                }
            }
        }
    }
}
--------------------------------------------------
// CONSOLE

[float]
===== Geohash

[source,js]
--------------------------------------------------
GET /_search
{
    "query": {
        "bool" : {
            "must" : {
                "match_all" : {}
            },
            "filter" : {
                "geo_bounding_box" : {
                    "pin.location" : {
                        "top_left" : "dr5r9ydj2y73",
                        "bottom_right" : "drj7teegpus6"
                    }
                }
            }
        }
    }
}
--------------------------------------------------
// CONSOLE


When geohashes are used to specify the bounding the edges of the
bounding box, the geohashes are treated as rectangles. The bounding
box is defined in such a way that its top left corresponds to the top
left corner of the geohash specified in the `top_left` parameter and
its bottom right is defined as the bottom right of the geohash
specified in the `bottom_right` parameter.

In order to specify a bounding box that would match entire area of a
geohash the geohash can be specified in both `top_left` and
`bottom_right` parameters:

[source,js]
--------------------------------------------------
GET /_search
{
    "query": {
        "geo_bounding_box" : {
            "pin.location" : {
                "top_left" : "dr",
                "bottom_right" : "dr"
            }
        }
    }
}
--------------------------------------------------
// CONSOLE

In this example, the geohash `dr` will produce the bounding box
query with the top left corner at `45.0,-78.75` and the bottom right
corner at `39.375,-67.5`.

[float]
==== Vertices

The vertices of the bounding box can either be set by `top_left` and
`bottom_right` or by `top_right` and `bottom_left` parameters. More
over the names `topLeft`, `bottomRight`, `topRight` and `bottomLeft`
are supported. Instead of setting the values pairwise, one can use
the simple names `top`, `left`, `bottom` and `right` to set the
values separately.

[source,js]
--------------------------------------------------
GET /_search
{
    "query": {
        "bool" : {
            "must" : {
                "match_all" : {}
            },
            "filter" : {
                "geo_bounding_box" : {
                    "pin.location" : {
                        "top" : 40.73,
                        "left" : -74.1,
                        "bottom" : 40.01,
                        "right" : -71.12
                    }
                }
            }
        }
    }
}
--------------------------------------------------
// CONSOLE


[float]
==== geo_point Type

The filter *requires* the `geo_point` type to be set on the relevant
field.

[float]
==== Multi Location Per Document

The filter can work with multiple locations / points per document. Once
a single location / point matches the filter, the document will be
included in the filter

[float]
[[geo-bbox-type]]
==== Type

The type of the bounding box execution by default is set to `memory`,
which means in memory checks if the doc falls within the bounding box
range. In some cases, an `indexed` option will perform faster (but note
that the `geo_point` type must have lat and lon indexed in this case).
Note, when using the indexed option, multi locations per document field
are not supported. Here is an example:

[source,js]
--------------------------------------------------
GET /_search
{
    "query": {
        "bool" : {
            "must" : {
                "match_all" : {}
            },
            "filter" : {
                "geo_bounding_box" : {
                    "pin.location" : {
                        "top_left" : {
                            "lat" : 40.73,
                            "lon" : -74.1
                        },
                        "bottom_right" : {
                            "lat" : 40.10,
                            "lon" : -71.12
                        }
                    },
                    "type" : "indexed"
                }
            }
        }
    }
}
--------------------------------------------------
// CONSOLE

[float]
==== Ignore Unmapped

When set to `true` the `ignore_unmapped` option will ignore an unmapped field
and will not match any documents for this query. This can be useful when
querying multiple indexes which might have different mappings. When set to
`false` (the default value) the query will throw an exception if the field
is not mapped.

[float]
==== Notes on Precision

Geopoints have limited precision and are always rounded down during index time.
During the query time, upper boundaries of the bounding boxes are rounded down,
while lower boundaries are rounded up. As a result, the points along on the
lower bounds (bottom and left edges of the bounding box) might not make it into
the bounding box due to the rounding error. At the same time points alongside
the upper bounds (top and right edges) might be selected by the query even if
they are located slightly outside the edge. The rounding error should be less
than 4.20e-8 degrees on the latitude and less than 8.39e-8 degrees on the
longitude, which translates to less than 1cm error even at the equator.
