public interface SchemaRelationProvider
Users may specify the fully qualified class name of a given data source. When that class is
not found Spark SQL will append the class name DefaultSource
to the path, allowing for
less verbose invocation. For example, 'org.apache.spark.sql.json' would resolve to the
data source 'org.apache.spark.sql.json.DefaultSource'
A new instance of this class will be instantiated each time a DDL call is made.
The difference between a RelationProvider
and a SchemaRelationProvider
is that
users need to provide a schema when using a SchemaRelationProvider
.
A relation provider can inherit both RelationProvider
and SchemaRelationProvider
if it can support both schema inference and user-specified schemas.
Modifier and Type | Method and Description |
---|---|
BaseRelation |
createRelation(SQLContext sqlContext,
scala.collection.immutable.Map<String,String> parameters,
StructType schema)
Returns a new base relation with the given parameters and user defined schema.
|
BaseRelation createRelation(SQLContext sqlContext, scala.collection.immutable.Map<String,String> parameters, StructType schema)
sqlContext
- (undocumented)parameters
- (undocumented)schema
- (undocumented)