Pure SQL environment
Starting from Sedona v1.0.1, you can use Sedona in a pure Spark SQL environment. The example code is written in SQL.
SedonaSQL supports SQL/MM Part3 Spatial SQL Standard. Detailed SedonaSQL APIs are available here: SedonaSQL API
Initiate Session¶
Start spark-sql as following (replace <VERSION> with actual version like 1.9.1):
Run spark-sql with Apache Sedona
spark-sql --packages org.apache.sedona:sedona-spark-shaded-3.5_2.12:<VERSION>,org.datasyslab:geotools-wrapper:1.9.1-33.5 \
--conf spark.serializer=org.apache.spark.serializer.KryoSerializer \
--conf spark.kryo.registrator=org.apache.sedona.viz.core.Serde.SedonaVizKryoRegistrator \
--conf spark.sql.extensions=org.apache.sedona.viz.sql.SedonaVizExtensions,org.apache.sedona.sql.SedonaSqlExtensions
Spark 4.0 and above are built with Scala 2.13 only. Replace the artifact with the one carrying your Spark major.minor version, such as sedona-spark-shaded-4.0_2.13 for Spark 4.0 or sedona-spark-shaded-4.1_2.13 for Spark 4.1.
This will register all Sedona types, functions and optimizations in SedonaSQL and SedonaViz.
Load data¶
Let use data from examples/sql. To load data from CSV file we need to execute two commands:
Use the following code to load the data and create a raw DataFrame:
CREATE TABLE IF NOT EXISTS pointraw (_c0 string, _c1 string)
USING csv
OPTIONS(header='false')
LOCATION '<some path>/sedona/examples/sql/src/test/resources/testpoint.csv';
CREATE TABLE IF NOT EXISTS polygonraw (_c0 string, _c1 string, _c2 string, _c3 string)
USING csv
OPTIONS(header='false')
LOCATION '<some path>/sedona/examples/sql/src/test/resources/testenvelope.csv';
Transform the data¶
We need to transform our point and polygon data into respective types:
CREATE OR REPLACE TEMP VIEW pointdata AS
SELECT ST_Point(cast(pointraw._c0 as Decimal(24,20)), cast(pointraw._c1 as Decimal(24,20))) AS pointshape
FROM pointraw;
CREATE OR REPLACE TEMP VIEW polygondata AS
select ST_PolygonFromEnvelope(cast(polygonraw._c0 as Decimal(24,20)),
cast(polygonraw._c1 as Decimal(24,20)), cast(polygonraw._c2 as Decimal(24,20)),
cast(polygonraw._c3 as Decimal(24,20))) AS polygonshape
FROM polygonraw;
Work with data¶
For example, let join polygon and test data:
SELECT * from polygondata, pointdata
WHERE ST_Contains(polygondata.polygonshape, pointdata.pointshape)
AND ST_Contains(ST_PolygonFromEnvelope(1.0,101.0,501.0,601.0), polygondata.polygonshape)
LIMIT 5;
GEOMETRY data type support¶
Sedona has a Spark SQL parser extension to support GEOMETRY data type in DDL statements. For example, you can specify a schema with a geometry column when creating the table:
CREATE TABLE geom_table (id STRING, version INT, geometry GEOMETRY)
USING geoparquet
LOCATION '/path/to/geoparquet_geom_table';
SELECT * FROM geom_table LIMIT 10;
The SQL parser extension is enabled by default. If you find it conflicting with other extensions and want to disable it,
please specify --conf spark.sedona.enableParserExtension=false when starting spark-sql.