64 lines
1.9 KiB
Plaintext
64 lines
1.9 KiB
Plaintext
[[query-dsl-geohash-cell-query]]
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=== Geohash Cell Query
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The `geohash_cell` query provides access to a hierarchy of geohashes.
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By defining a geohash cell, only <<geo-point,geopoints>>
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within this cell will match this filter.
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To get this filter work all prefixes of a geohash need to be indexed. In
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example a geohash `u30` needs to be decomposed into three terms: `u30`,
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`u3` and `u`. This decomposition must be enabled in the mapping of the
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<<geo-point,geopoint>> field that's going to be filtered by
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setting the `geohash_prefix` option:
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[source,js]
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--------------------------------------------------
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{
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"mappings" : {
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"location": {
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"properties": {
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"pin": {
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"type": "geo_point",
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"geohash": true,
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"geohash_prefix": true,
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"geohash_precision": 10
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}
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}
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}
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}
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}
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--------------------------------------------------
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The geohash cell can defined by all formats of `geo_points`. If such a cell is
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defined by a latitude and longitude pair the size of the cell needs to be
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setup. This can be done by the `precision` parameter of the filter. This
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parameter can be set to an integer value which sets the length of the geohash
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prefix. Instead of setting a geohash length directly it is also possible to
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define the precision as distance, in example `"precision": "50m"`. (See
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<<distance-units>>.)
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The `neighbor` option of the filter offers the possibility to filter cells
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next to the given cell.
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[source,js]
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--------------------------------------------------
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{
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"bool" : {
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"must" : {
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"match_all" : {}
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},
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"filter" : {
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"geohash_cell": {
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"pin": {
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"lat": 13.4080,
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"lon": 52.5186
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},
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"precision": 3,
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"neighbors": true
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}
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}
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}
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}
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--------------------------------------------------
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