Package io.debezium.connector.postgresql.spi

Interface Snapshotter

All Known Implementing Classes:

AlwaysSnapshotter, InitialOnlySnapshotter, InitialSnapshotter, NeverSnapshotter, QueryingSnapshotter

@Incubating
public interface Snapshotter

This interface is used to determine details about the snapshot process: Namely: - Should a snapshot occur at all - Should streaming occur - What queries should be used to snapshot While many default snapshot modes are provided with debezium (see documentation for details) a custom implementation of this interface can be provided by the implementor which can provide more advanced functionality, such as partial snapshots Implementor's must return true for either shouldSnapshot() or shouldStream() or true for both.

Method Summary

Modifier and Type	Method	Description
Optional<String>	buildSnapshotQuery(TableId tableId, List<String> snapshotSelectColumns)	Generate a valid postgres query string for the specified table, or an empty Optional to skip snapshotting this table (but that table will still be streamed from)
void	init(PostgresConnectorConfig config, OffsetState sourceInfo, SlotState slotState)
boolean	shouldSnapshot()
boolean	shouldStream()
default boolean	shouldStreamEventsStartingFromSnapshot()
default void	snapshotCompleted()	Lifecycle hook called once the snapshot phase is finished.
default Optional<String>	snapshotTableLockingStatement(Duration lockTimeout, Set<TableId> tableIds)	Returns a SQL statement for locking the given tables during snapshotting, if required by the specific snapshotter implementation.
default String	snapshotTransactionIsolationLevelStatement(SlotCreationResult newSlotInfo)	Return a new string that set up the transaction for snapshotting

Method Detail

init

void init(PostgresConnectorConfig config,
          OffsetState sourceInfo,
          SlotState slotState)

shouldSnapshot

boolean shouldSnapshot()

Returns:

true if the snapshotter should take a snapshot

shouldStream

boolean shouldStream()

Returns:

true if the snapshotter should stream after taking a snapshot

shouldStreamEventsStartingFromSnapshot

default boolean shouldStreamEventsStartingFromSnapshot()

Returns:

true if streaming should resume from the start of the snapshot transaction, or false for when a connector resumes and takes a snapshot, streaming should resume from where streaming previously left off.

buildSnapshotQuery

Optional<String> buildSnapshotQuery(TableId tableId,
                                    List<String> snapshotSelectColumns)

Generate a valid postgres query string for the specified table, or an empty Optional to skip snapshotting this table (but that table will still be streamed from)

Parameters:

tableId - the table to generate a query for

snapshotSelectColumns - the columns to be used in the snapshot select based on the column include/exclude filters

Returns:

a valid query string, or none to skip snapshotting this table

snapshotTransactionIsolationLevelStatement

default String snapshotTransactionIsolationLevelStatement(SlotCreationResult newSlotInfo)

Return a new string that set up the transaction for snapshotting

Parameters:

newSlotInfo - if a new slow was created for snapshotting, this contains information from the `create_replication_slot` command

snapshotTableLockingStatement

default Optional<String> snapshotTableLockingStatement(Duration lockTimeout,
                                                       Set<TableId> tableIds)

Returns a SQL statement for locking the given tables during snapshotting, if required by the specific snapshotter implementation.

snapshotCompleted

default void snapshotCompleted()

Lifecycle hook called once the snapshot phase is finished.