Solr Spatial Search
三种fieldType：
LatLonType
SpatialRecursivePrefixTreeFieldType（RPT）
BBoxField
Spatial Filters:
geofilt
&q=*:*&fq={!geofilt sfield=store}&pt=45.15,-93.85&d=5
all the results within the circle of the given radius around the initial point
bbox
&q=*:*&fq={!bbox sfield=store}&pt=45.15,-93.85&d=5.
all the results in the box
specify large distErrPct value , the filter will run faster
arbitrary rectangle
RPT support
solr post filter
&q=...mykeywords...&fq=...someotherfilters...&fq={!geofilt cache=false cost=100}&sfield=store&pt=45.15,-93.85&d=5
distance function queries
geodist,dist,hsin,sqedist
geodist
sort result by distance asc
&q=*:*&fq={!geofilt}&sfield=store&pt=45.15,-93.85&d=50&sort=geodist asc
return distance as the document score
&q={!func}geodist()&sfield=store&pt=45.15,-93.85&sort=score+asc
More examples
use as a sub-query to expand the search results
Here we will query for results in Jacksonville, Florida, or within 50 kilometers of 45.15,-93.85 (near Buffalo, Minnesota):
&q=*:*&fq=(state:"FL" AND city:"Jacksonville") OR {!geofilt}&sfield=store&pt=45.15,-93.85&d=50&sort=geodist()+asc
facet by distance
To facet by distance, you can use the Frange query parser:
&q=*:*&sfield=store&pt=45.15,-93.85&facet.query={!frange l=0 u=5}geodist()&facet.query={!frange l=5.001 u=3000}geodist()
There are other ways to do it too, like using a {!geofilt} in each facet.query.
boost nearest results
&q.alt=*:*&fq={!geofilt}&sfield=store&pt=45.15,-93.85&d=50&bf=recip(geodist(),2,200,20)&sort=score desc
SpatialRecursivePrefixTreeFieldType (abbreviated as RPT)
Solr 4's new spatial field offers several new features and improvements over LatLonType:
- Query by polygons and other complex shapes, in addition to circles & rectangles
- Multi-valued indexed fields
- Ability to index non-point shapes (e.g. polygons) as well as point shapes
- Rectangles with user-specified corners that can cross the dateline
- Multi-value distance sort and score boosting (warning: non-optimized)
- Well-Known-Text (WKT) shape syntax (required for specifying polygons & other complex shapes)
RPT schema
class
distErrPct指中心点与边界距离的精确度，【0.0---0.5】越小越精确，索引慢，占用磁盘越多，查询慢，反之则反
geo 默认值为true，将应用经纬度坐标，数学模型是一个球体，false则是二维的xy坐标
maxDistErr 定义索引数据的详细程度，默认一米，只比0.000009 degrees小一点，这个设置用来在内部计算恰当的maxLevels
maxLevels 设置索引数据的最大格子深度，更直观的是通过指定maxDistErr来计算恰当的maxLevels
name
prefixTree 定义spatial grid的实现，prefixTree把一个地域范围映射成一个grid，每一个grid被分解成一系列下一级的sub grid ，如果geo=false默认的prefix tree是geohash，否则是quad，geohash有32个孩子grid，quad有4个。
spatialContextFactory 如果使用多边形，则需要指定它的实现（com.spatial4j.core.context.jts.JtsSpatialContextFactory），设置autoIndex=true提升多边形的性能
units 现在只能是degrees，是用来计算maxDistErr的，1degree大约111.2千米
worldBounds 如果geo=false则需要指定worldBounds，format ： ENVELOPE(minX, maxX, maxY, minY)
samples
<fieldType name="location_rpt" class="solr.SpatialRecursivePrefixTreeFieldType" spatialContextFactory="com.spatial4j.core.context.jts.JtsSpatialContextFactory" autoIndex="true" distErrPct="0.025" maxDistErr="0.000009" units="degrees" />BBoxField
BBoxField索引一个矩形，支持通过boundary box 查询
samples
<field name="bbox" type="bbox" /><fieldType name="bbox" class="solr.BBoxField" geo="true" units="degrees" numberType="_bbox_coord" /><fieldType name="_bbox_coord" class="solr.TrieDoubleField" precisionStep="8" docValues="true" stored="false"/>The latter is the only way to choose a predicate other than Intersects. For example:
&q={!field f=bbox}Contains(ENVELOPE(-10, 20, 15, 10))
Now to sort the results by one of the relevancy modes, use it like this:
&q={!field f=bbox score=overlapRatio}Intersects(ENVELOPE(-10, 20, 15, 10))
You can also use&debug=results to see useful score computation info.
