@PublicEvolving public abstract class DataType extends Object implements AbstractDataType<DataType>, Serializable
The DataType
class has two responsibilities: declaring a logical type and giving hints
about the physical representation of data to the planner. While the logical type is mandatory,
hints are optional but useful at the edges to other APIs.
The logical type is independent of any physical representation and is close to the "data type"
terminology of the SQL standard. See LogicalType
and
its subclasses for more information about available logical types and their properties.
Physical hints are required at the edges of the table ecosystem. Hints indicate the data
format that an implementation expects. For example, a data source could express that it produces
values for logical timestamps using a Timestamp
class instead of using LocalDateTime
. With this information, the runtime is able to convert the produced
class into its internal data format. In return, a data sink can declare the data format it
consumes from the runtime.
Modifier and Type | Field and Description |
---|---|
protected Class<?> |
conversionClass |
protected LogicalType |
logicalType |
Modifier and Type | Method and Description |
---|---|
abstract <R> R |
accept(DataTypeVisitor<R> visitor) |
boolean |
equals(Object o) |
abstract List<DataType> |
getChildren() |
Class<?> |
getConversionClass()
Returns the corresponding conversion class for representing values.
|
LogicalType |
getLogicalType()
Returns the corresponding logical type.
|
int |
hashCode() |
String |
toString() |
clone, finalize, getClass, notify, notifyAll, wait, wait, wait
bridgedTo, notNull, nullable
protected final LogicalType logicalType
protected final Class<?> conversionClass
public LogicalType getLogicalType()
LogicalType
public Class<?> getConversionClass()
LogicalType.getDefaultConversion()
public abstract <R> R accept(DataTypeVisitor<R> visitor)
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