Package org.apache.beam.sdk.io.gcp.spanner

Class ReadSpannerSchema

java.lang.Object

org.apache.beam.sdk.transforms.DoFn<Void,SpannerSchema>

org.apache.beam.sdk.io.gcp.spanner.ReadSpannerSchema

All Implemented Interfaces:

Serializable, HasDisplayData

public class ReadSpannerSchema
extends DoFn<Void,SpannerSchema>

This DoFn reads Cloud Spanner 'information_schema.*' tables to build the SpannerSchema.

See Also:

• Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.beam.sdk.transforms.DoFn

DoFn.AlwaysFetched, DoFn.BoundedPerElement, DoFn.BundleFinalizer, DoFn.Element, DoFn.FieldAccess, DoFn.FinishBundle, DoFn.FinishBundleContext, DoFn.GetInitialRestriction, DoFn.GetInitialWatermarkEstimatorState, DoFn.GetRestrictionCoder, DoFn.GetSize, DoFn.GetWatermarkEstimatorStateCoder, DoFn.Key, DoFn.MultiOutputReceiver, DoFn.NewTracker, DoFn.NewWatermarkEstimator, DoFn.OnTimer, DoFn.OnTimerContext, DoFn.OnTimerFamily, DoFn.OnWindowExpiration, DoFn.OnWindowExpirationContext, DoFn.OutputReceiver<T>, DoFn.ProcessContext, DoFn.ProcessContinuation, DoFn.ProcessElement, DoFn.RequiresStableInput, DoFn.RequiresTimeSortedInput, DoFn.Restriction, DoFn.Setup, DoFn.SideInput, DoFn.SplitRestriction, DoFn.StartBundle, DoFn.StartBundleContext, DoFn.StateId, DoFn.Teardown, DoFn.TimerFamily, DoFn.TimerId, DoFn.Timestamp, DoFn.TruncateRestriction, DoFn.UnboundedPerElement, DoFn.WatermarkEstimatorState, DoFn.WindowedContext

Constructor Summary

Constructors

Constructor	Description
ReadSpannerSchema(SpannerConfig config, PCollectionView<Dialect> dialectView)	Constructor for creating an instance of the ReadSpannerSchema class.
ReadSpannerSchema(SpannerConfig config, PCollectionView<Dialect> dialectView, Set<String> allowedTableNames)	Constructor for creating an instance of the ReadSpannerSchema class.

Method Summary

Modifier and Type	Method	Description
void	processElement(DoFn<Void,SpannerSchema>.ProcessContext c)
void	setup()
void	teardown()

Methods inherited from class org.apache.beam.sdk.transforms.DoFn

getAllowedTimestampSkew, getInputTypeDescriptor, getOutputTypeDescriptor, populateDisplayData, prepareForProcessing

Methods inherited from class java.lang.Object

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

Constructor Details

ReadSpannerSchema

public ReadSpannerSchema(SpannerConfig config,
 PCollectionView<Dialect> dialectView)

Constructor for creating an instance of the ReadSpannerSchema class. If no is passed, every single table is allowed.

Parameters:

config - The SpannerConfig object that contains the configuration for accessing the Spanner database.

dialectView - A PCollectionView object that holds a Dialect object for the database dialect to use for reading the Spanner schema.

ReadSpannerSchema

public ReadSpannerSchema(SpannerConfig config,
 PCollectionView<Dialect> dialectView,
 Set<String> allowedTableNames)

Constructor for creating an instance of the ReadSpannerSchema class.

Parameters:

config - The SpannerConfig object that contains the configuration for accessing the Spanner database.

dialectView - A PCollectionView object that holds a Dialect object for the database dialect to use for reading the Spanner schema.

allowedTableNames - A set of allowed table names to be used when reading the Spanner schema.

Method Details

setup

@Setup
public void setup()
           throws Exception

Throws:

Exception

teardown

@Teardown
public void teardown()
              throws Exception

Throws:

Exception

processElement

@ProcessElement
public void processElement(DoFn<Void,SpannerSchema>.ProcessContext c)
                    throws Exception

Throws:

Exception