SparkSQL --> XML Schema datatypes conversion in OntopSpark

SparkSQL reference : https://spark.apache.org/docs/latest/sql-ref-datatypes.html

W3C reccomended mappings : https://www.w3.org/2001/sw/rdb2rdf/wiki/Mapping_SQL_datatypes_to_XML_Schema_datatypes

Spark datatype	SparkSQL name	W3C reccomandation	ONTOP default	OntopSpark
BooleanType	BOOLEAN	xsd:boolean	xsd:boolean
ByteType	BYTE, TINYINT	xsd:integer or subtype	xsd:integer	xsd:byte
ShortType	SHORT, SMALLINT	xsd:integer or subtype	xsd:integer	xsd:short
IntegerType	INT, INTEGER	xsd:integer or subtype	xsd:integer	xsd:int
LongType	LONG, BIGINT	xsd:integer or subtype	xsd:integer	xsd:long
FloatType	FLOAT, REAL	xsd:float or xsd:double	xsd:double	xsd:float
DoubleType	DOUBLE	xsd:double	xsd:double
DateType	DATE	xsd:date	xsd:date
TimestampType	TIMESTAMP	xsd:dateTime	xsd:dateTime
StringType	STRING	xsd:string	xsd:string
BinaryType	BINARY	xsd:hexBinary or xsd:base64Binary	xsd:hexBinary
DecimalType	DECIMAL, DEC, NUMERIC	xsd:decimal	xsd:decimal

Running the test

1. Build and run Apache Spark

foo@bar:~$ sudo ./docker-build.sh
foo@bar:~$ sudo docker-compose -f docker-compose-spark.yml up

2. Wait Apache Spark complete startup, then run OntopSpark in another console window

foo@bar:~$ sudo docker-compose -f docker-compose-ontop.yml up

2. Connect to localhost:8080

3. Execute the query, and check the datatypes

PREFIX : <http://www.semanticweb.org/spark-datatypes-test#>

SELECT * WHERE {
  ?sub ?pred ?obj .
}