public abstract class BaseRelation
extends Object
StructType
Concrete
implementation should inherit from one of the descendant Scan
classes, which define various
abstract methods for execution.
BaseRelations must also define a equality function that only returns true when the two instances will return the same data. This equality function is used when determining when it is safe to substitute cached results for a given relation.
Constructor and Description |
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BaseRelation() |
Modifier and Type | Method and Description |
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abstract org.apache.spark.sql.catalyst.types.StructType |
schema() |
long |
sizeInBytes()
Returns an estimated size of this relation in bytes.
|
abstract SQLContext |
sqlContext() |
public abstract SQLContext sqlContext()
public abstract org.apache.spark.sql.catalyst.types.StructType schema()
public long sizeInBytes()