org.apache.flink.table.descriptors

Class TableDescriptor<D extends TableDescriptor<D>>

java.lang.Object

org.apache.flink.table.descriptors.DescriptorBase

org.apache.flink.table.descriptors.TableDescriptor<D>

Type Parameters:

D - return type for builder pattern

All Implemented Interfaces:

Descriptor

Direct Known Subclasses:

CatalogTableBuilder, ConnectTableDescriptor

@PublicEvolving
public abstract class TableDescriptor<D extends TableDescriptor<D>>
extends DescriptorBase

Describes a table consisting of a connector (in a given update mode) and a format.

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	TableDescriptor(ConnectorDescriptor connectorDescriptor)

Method Summary

Modifier and Type	Method and Description
protected Map<String,String>	additionalProperties() Enables adding more specific properties to toProperties().
D	inAppendMode() Declares how to perform the conversion between a dynamic table and an external connector.
D	inRetractMode() Declares how to perform the conversion between a dynamic table and an external connector.
D	inUpsertMode() Declares how to perform the conversion between a dynamic table and an external connector.
Map<String,String>	toProperties() Converts this descriptor into a set of properties.
D	withFormat(FormatDescriptor format) Specifies the format that defines how to read data from a connector.

Methods inherited from class org.apache.flink.table.descriptors.DescriptorBase

toString

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

TableDescriptor

protected TableDescriptor(ConnectorDescriptor connectorDescriptor)

Method Detail

withFormat

public D withFormat(FormatDescriptor format)

Specifies the format that defines how to read data from a connector.

inAppendMode

public D inAppendMode()

Declares how to perform the conversion between a dynamic table and an external connector.

In append mode, a dynamic table and an external connector only exchange INSERT messages.

See Also:

inRetractMode(), inUpsertMode()

inRetractMode

public D inRetractMode()

Declares how to perform the conversion between a dynamic table and an external connector.

In retract mode, a dynamic table and an external connector exchange ADD and RETRACT messages.

An INSERT change is encoded as an ADD message, a DELETE change as a RETRACT message, and an UPDATE change as a RETRACT message for the updated (previous) row and an ADD message for the updating (new) row.

In this mode, a key must not be defined as opposed to upsert mode. However, every update consists of two messages which is less efficient.

See Also:

inAppendMode(), inUpsertMode()

inUpsertMode

public D inUpsertMode()

Declares how to perform the conversion between a dynamic table and an external connector.

In upsert mode, a dynamic table and an external connector exchange UPSERT and DELETE messages.

This mode requires a (possibly composite) unique key by which updates can be propagated. The external connector needs to be aware of the unique key attribute in order to apply messages correctly. INSERT and UPDATE changes are encoded as UPSERT messages. DELETE changes as DELETE messages.

The main difference to a retract stream is that UPDATE changes are encoded with a single message and are therefore more efficient.

See Also:

inAppendMode(), inRetractMode()

toProperties

public final Map<String,String> toProperties()

Converts this descriptor into a set of properties.

additionalProperties

protected Map<String,String> additionalProperties()

Enables adding more specific properties to toProperties().