{
  "query": {
    "sql2008": "http://www.w3.org/ns/r2rml#SQL2008",
    "oracle": "http://www.w3.org/ns/r2rml#Oracle",
    "mysql": "http://www.w3.org/ns/r2rml#MySQL",
    "mssql": "http://www.w3.org/ns/r2rml#MSSQLServer",
    "hsql": "http://www.w3.org/ns/r2rml#HSQLDB",
    "postgresql": "http://www.w3.org/ns/r2rml#PostgreSQL",
    "db2": "http://www.w3.org/ns/r2rml#DB2",
    "informix": "Informix",
    "ingres": "http://www.w3.org/ns/r2rml#Ingres",
    "progress": "http://www.w3.org/ns/r2rml#Progress",
    "sybasease": "http://www.w3.org/ns/r2rml#SybaseASE",
    "sybasesqlanywhere": "http://www.w3.org/ns/r2rml#SybaseSQLAnywhere",
    "virtuoso": "http://www.w3.org/ns/r2rml#Virtuoso",
    "firebird": "http://www.w3.org/ns/r2rml#Firebird"
  },

  "reference": {
    "jsonpath": "http://semweb.mmlab.be/ns/ql#JSONPath",
    "xpath": "http://semweb.mmlab.be/ns/ql#XPath",
    "csv": "http://semweb.mmlab.be/ns/ql#CSV",
    "css3": "http://semweb.mmlab.be/ns/ql#CSS3"
  }
}