Lucene Spatial

(Versions 2.2 and after only, otherwise look at Legacy section)

This module is provided as external plugin. You can find it bundled in the GeoSpatial distribution, or you can add this plugin by yourself into any OrientDB distribution (Community and Enterprise Editions).

Install

Download the plugin jar from maven central:

http://central.maven.org/maven2/com/orientechnologies/orientdb-spatial/2.2.30/orientdb-spatial-2.2.30-dist.jar

After download, copy the jar to OrientDB lib directory (please make sure that the version of your OrientDB server and the version of the plugin are the same. Upgrade your OrientDB server, if necessary). On *nix system it could be done this way:

wget http://central.maven.org/maven2/com/orientechnologies/orientdb-spatial/2.2.30/orientdb-spatial-2.2.30-dist.jar
cp orientdb-spatial-2.2.30-dist.jar /PATH/orientdb-community-2.2.30/lib/

OrientDB will load the spatial plugin on startup.

Orient db will load the spatial plugin on startup.

Geometry Data

OrientDB supports the following Geometry objects :

  • Point (OPoint)
  • Line (OLine)
  • Polygon (OPolygon)
  • MultiPoint (OMultiPoint)
  • MultiLine (OMultiline)
  • MultiPolygon (OMultiPlygon)
  • Geometry Collections

OrientDB stores those objects like embedded documents with special classes. The module creates abstract classes that represent each Geometry object type, and those classes can be embedded in user defined classes to provide geospatial information.

Each spatial classes (Geometry Collection excluded) comes with field coordinates that will be used to store the geometry structure. The "coordinates" field of a geometry object is composed of one position (Point), an array of positions (LineString or MultiPoint), an array of arrays of positions (Polygons, MultiLineStrings) or a multidimensional array of positions (MultiPolygon).

Geometry data Example

Restaurants Domain

CREATE class Restaurant
CREATE PROPERTY Restaurant.name STRING
CREATE PROPERTY Restaurant.location EMBEDDED OPoint

To insert restaurants with location

From SQL

INSERT INTO  Restaurant SET name = 'Dar Poeta', location = {"@class": "OPoint","coordinates" : [12.4684635,41.8914114]}

or as an alternative, if you use WKT format you can use the function ST_GeomFromText to create the OrientDB geometry object.

INSERT INTO  Restaurant SET name = 'Dar Poeta', location = St_GeomFromText("POINT (12.4684635 41.8914114)")

From JAVA

ODocument location = new ODocument("OPoint");
location.field("coordinates", Arrays.asList(12.4684635, 41.8914114));

ODocument doc = new ODocument("Restaurant");
doc.field("name","Dar Poeta");
doc.field("location",location);

doc.save();

A spatial index on the location field s defined by

CREATE INDEX Restaurant.location ON Restaurant(location) SPATIAL ENGINE LUCENE"

Spatial Reference System

OrientDB supports only EPSG:4326 as Spatial Reference System

Functions

OrientDB follows The Open Geospatial Consortium OGC for extending SQL to support spatial data. OrientDB implements a subset of SQL-MM functions with ST prefix (Spatial Type)

ST_AsText

Syntax : ST_AsText(geom)

Example

SELECT ST_AsText({"@class": "OPoint","coordinates" : [12.4684635,41.8914114]})

Result
----------
POINT (12.4684635 41.8914114)

ST_GeomFromText

Syntax : ST_GeomFromText(text)

Example

select ST_GeomFromText("POINT (12.4684635 41.8914114)")

Result
----------------------------------------------------------------------------------
{"@type":"d","@version":0,"@class":"OPoint","coordinates":[12.4684635,41.8914114]}

ST_Equals

Returns true if geom1 is spatially equal to geom2

Syntax : ST_Equals(geom1,geom2)

Example


SELECT ST_Equals(ST_GeomFromText('LINESTRING(0 0, 10 10)'), ST_GeomFromText('LINESTRING(0 0, 5 5, 10 10)'))

Result
-----------
true

ST_Within

Returns true if geom1 is inside geom2

Syntax : ST_Within(geom1,geom2)

This function will use an index if available.

Example

select * from City where  ST_WITHIN(location,'POLYGON ((12.314015 41.8262816, 12.314015 41.963125, 12.6605063 41.963125, 12.6605063 41.8262816, 12.314015 41.8262816))') = true

ST_Distance

Returns the 2D Cartesian distance between two geometries

Syntax : ST_Distance(geom1,geom2)

Example

select ST_Distance(ST_GEOMFROMTEXT('POINT(12.4662748 41.8914114)'),ST_GEOMFROMTEXT('POINT(12.4664632 41.8904382)')) as distance

distance
--------
0.0009912682785239528

ST_Distance_Sphere (From OrientDB 2.2.4)

Returns the distance between two geometries in meters using a spherical earth. Supports Only Points. This function will use an index if available (Only if the condition is < or <=).

Example

SELECT ST_Distance_Sphere(ST_GeomFromText('POINT(12.4686519 41.890438)'), ST_GeomFromText('POINT(12.468933 41.890303)')) as distance

In where condition

SELECT from Place where ST_Distance_Sphere(location, ST_GeomFromText('POINT(12.468933 41.890303)')) < 50

ST_DWithin

Returns true if the geometries are within the specified distance of one another

Syntax : ST_DWithin(geom1,geom2,distance)

Example

SELECT ST_DWithin(ST_GeomFromText('POLYGON((0 0, 10 0, 10 5, 0 5, 0 0))'), ST_GeomFromText('POLYGON((12 0, 14 0, 14 6, 12 6, 12 0))'), 2.0d) as distance
SELECT from Polygon where ST_DWithin(geometry, ST_GeomFromText('POLYGON((12 0, 14 0, 14 6, 12 6, 12 0))'), 2.0) = true

ST_Contains

Returns true if geom1 contains geom2

Syntax : ST_Contains(geom1,geom2)

This function will use an index if available.

Example

SELECT ST_Contains(ST_Buffer(ST_GeomFromText('POINT(0 0)'),10),ST_GeomFromText('POINT(0 0)'))

Result
----------
true
SELECT ST_Contains(ST_Buffer(ST_GeomFromText('POINT(0 0)'),10),ST_Buffer(ST_GeomFromText('POINT(0 0)'),20))

Result
----------
false

ST_Disjoint

Returns true if geom1 does not spatially intersects geom2

Syntax: St_Disjoint(geom1,geom2)

This function does not use indexes

Example

SELECT ST_Disjoint(ST_GeomFromText('POINT(0 0)'), ST_GeomFromText('LINESTRING ( 2 0, 0 2 )'));

Result
-----------------
true
SELECT ST_Disjoint(ST_GeomFromText('POINT(0 0)'), ST_GeomFromText('LINESTRING ( 0 0, 0 2 )'));

Result
-----------------
false

ST_Intersects

Returns true if geom1 spatially intersects geom2

Syntax: ST_Intersects(geom1,geom2)

Example

SELECT ST_Intersects(ST_GeomFromText('POINT(0 0)'), ST_GeomFromText('LINESTRING ( 2 0, 0 2 )'));

Result
-------------
false
SELECT ST_Intersects(ST_GeomFromText('POINT(0 0)'), ST_GeomFromText('LINESTRING ( 0 0, 0 2 )'));

Result
-------------
true

ST_AsBinary

Returns the Well-Known Binary (WKB) representation of the geometry

Syntax : ST_AsBinary(geometry)

Example

SELECT ST_AsBinary(ST_GeomFromText('POINT(0 0)'))

ST_Envelope

Returns a geometry representing the bounding box of the supplied geometry

Syntax : ST_Envelope(geometry)

Example

SELECT ST_AsText(ST_Envelope(ST_GeomFromText('POINT(1 3)')));

Result
----------
POINT (1 3)
SELECT ST_AsText(ST_Envelope(ST_GeomFromText('LINESTRING(0 0, 1 3)')))

Result
-----------------------------------
POLYGON ((0 0, 0 3, 1 3, 1 0, 0 0))

ST_Buffer

Returns a geometry that represents all points whose distance from this Geometry is less than or equal to distance.

Syntax: ST_Buffer(geometry,distance [,config])

where config is an additional parameter (JSON) that can be use to set:

quadSegs: int -> number of segments used to approximate a quarter circle (defaults to 8).

{ 
  quadSegs : 1
}

endCap : round|flat|square -> endcap style (defaults to "round").

{
  endCap : 'square'
}

join : round|mitre|bevel -> join style (defaults to "round")

{ 
  join : 'bevel'
}

mitre : double -> mitre ratio limit (only affects mitered join style).

{ 
  join : 'mitre', 
  mitre : 5.0
}

Example

SELECT ST_AsText(ST_Buffer(ST_GeomFromText('POINT(100 90)'),50))
SELECT ST_AsText(ST_Buffer(ST_GeomFromText('POINT(100 90)'), 50, { quadSegs : 2 }));

Operators

A && B

Overlaps operator. Returns true if bounding box of A overlaps bounding box of B. This operator will use an index if available.

Example

CREATE CLASS TestLineString
CREATE PROPERTY TestLineString.location EMBEDDED OLineString
INSERT INTO TestLineSTring SET name = 'Test1' , location = St_GeomFromText("LINESTRING(0 0, 3 3)")
INSERT INTO TestLineSTring SET name = 'Test2' , location = St_GeomFromText("LINESTRING(0 1, 0 5)")
SELECT FROM TestLineString WHERE location && "LINESTRING(1 2, 4 6)"

Spatial Indexes

To speed up spatial search and match condition, spatial operators and functions can use a spatial index if defined to avoid sequential full scan of every records.

The current spatial index implementation is built upon lucene-spatial.

The syntax for creating a spatial index on a geometry field is :

CREATE INDEX <name> ON <class-name> (geometry-field) SPATIAL ENGINE LUCENE

Legacy

Before v2.2, OrientDB was able to only index Points. Other Shapes like rectangles and polygons are managed starting from v2.2 (look above). This is the legacy section for databases created before v2.2. NOTE: If you are migrating to 2.2.x from 2.1.x and you are going to index null values, remember to add ignoreNullValues: true to the index definition:

CREATE INDEX Place.l_lon ON Place(latitude,longitude) SPATIAL ENGINE LUCENE METADATA {ignoreNullValues: true}

How to create a Spatial Index

The index can be created on a class that has two fields declared as DOUBLE (latitude,longitude) that are the coordinates of the Point.

For example we have a class Place with 2 double fields latitude and longitude. To create the spatial index on Place use this syntax.

CREATE INDEX Place.l_lon ON Place(latitude,longitude) SPATIAL ENGINE LUCENE

The Index can also be created with the Java Api. Example:

OSchema schema = databaseDocumentTx.getMetadata().getSchema();
OClass oClass = schema.createClass("Place");
oClass.createProperty("latitude", OType.DOUBLE);
oClass.createProperty("longitude", OType.DOUBLE);
oClass.createProperty("name", OType.STRING);
oClass.createIndex("Place.latitude_longitude", "SPATIAL", null, null, "LUCENE", new String[] { "latitude", "longitude" });

How to query the Spatial Index

Two custom operators has been added to query the Spatial Index:

  1. NEAR: to find all Points near a given location (latitude, longitude)
  2. WITHIN: to find all Points that are within a given Shape

NEAR operator

Finds all Points near a given location (latitude, longitude).

Syntax
SELECT FROM Class WHERE [<lat-field>,<long-field>] NEAR [lat,lon]

To specify maxDistance we have to pass a special variable in the context:

SELECT FROM Class WHERE [<lat-field>,<long-field>,$spatial] NEAR [lat,lon,{"maxDistance": distance}]

The maxDistance field has to be in kilometers, not radians. Results are sorted from nearest to farthest.

To know the exact distance between your Point and the Points matched, use the special variable in the context $distance.

SELECT *, $distance FROM Class WHERE [<lat-field>,<long-field>,$spatial] NEAR [lat,lon,{"maxDistance": distance}]
Examples

Let's take the example we have written before. We have a Spatial Index on Class Place on properties latitude and longitude.

Example: How to find the nearest Place of a given point:

SELECT *,$distance FROM Place WHERE [latitude,longitude,$spatial] NEAR [51.507222,-0.1275,{"maxDistance":1}]

WITHIN operator

Finds all Points that are within a given Shape.

The current release supports only Bounding Box shape
Syntax
SELECT FROM Class WHERE [<lat field>,<long field>] WITHIN [ [ <lat1>, <lon1> ] , [ <lat2>, <lon2> ] ... ]
Examples

Example with previous configuration:

SELECT * FROM Places WHERE [latitude,longitude] WITHIN [[51.507222,-0.1275],[55.507222,-0.1275]]

This query will return all Places within the given Bounding Box.

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