geo-distance-filter.asciidoc

Geo Distance Filter

Filters documents that include only hits that exists within a specific distance from a geo point. Assuming the following indexed json:

{
    "pin" : {
        "location" : {
            "lat" : 40.12,
            "lon" : -71.34
        }
    }
}

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

{
    "filtered" : {
        "query" : {
            "match_all" : {}
        },
        "filter" : {
            "geo_distance" : {
                "distance" : "200km",
                "pin.location" : {
                    "lat" : 40,
                    "lon" : -70
                }
            }
        }
    }
}

Accepted Formats

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

Lat Lon As Properties

{
    "filtered" : {
        "query" : {
            "match_all" : {}
        },
        "filter" : {
            "geo_distance" : {
                "distance" : "12km",
                "pin.location" : {
                    "lat" : 40,
                    "lon" : -70
                }
            }
        }
    }
}

Lat Lon As Array

Format in [lon, lat], note, the order of lon/lat here in order to conform with GeoJSON.

{
    "filtered" : {
        "query" : {
            "match_all" : {}
        },
        "filter" : {
            "geo_distance" : {
                "distance" : "12km",
                "pin.location" : [40, -70]
            }
        }
    }
}

Lat Lon As String

Format in lat,lon.

{
    "filtered" : {
        "query" : {
            "match_all" : {}
        },
        "filter" : {
            "geo_distance" : {
                "distance" : "12km",
                "pin.location" : "40,-70"
            }
        }
    }
}

Geohash

{
    "filtered" : {
        "query" : {
            "match_all" : {}
        },
        "filter" : {
            "geo_distance" : {
                "distance" : "12km",
                "pin.location" : "drm3btev3e86"
            }
        }
    }
}

Options

The following are options allowed on the filter:

distance	The radius of the circle centred on the specified location. Points which fall into this circle are considered to be matches. The distance can be specified in various units. See [distance-units].
distance_type	How to compute the distance. Can either be arc (better precision), sloppy_arc (faster but less precise) or plane (fastest). Defaults to sloppy_arc.
optimize_bbox	Whether to use the optimization of first running a bounding box check before the distance check. Defaults to memory which will do in memory checks. Can also have values of indexed to use indexed value check (make sure the geo_point type index lat lon in this case), or none which disables bounding box optimization.

geo_point Type

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

Multi Location Per Document

The geo_distance 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.

Caching

The result of the filter is not cached by default. The _cache can be set to true to cache the result of the filter. This is handy when the same point and distance parameters are used on several (many) other queries. Note, the process of caching the first execution is higher when caching (since it needs to satisfy different queries).