public class CreateTables<DestinationT,ElementT> extends PTransform<PCollection<KV<DestinationT,ElementT>>,PCollection<KV<TableDestination,ElementT>>>
DoFn
, and returns the original collection unchanged.name, resourceHints
Constructor and Description |
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CreateTables(BigQueryIO.Write.CreateDisposition createDisposition,
DynamicDestinations<?,DestinationT> dynamicDestinations)
The list of tables created so far, so we don't try the creation each time.
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Modifier and Type | Method and Description |
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PCollection<KV<TableDestination,ElementT>> |
expand(PCollection<KV<DestinationT,ElementT>> input)
Override this method to specify how this
PTransform should be expanded on the given
InputT . |
compose, compose, getAdditionalInputs, getDefaultOutputCoder, getDefaultOutputCoder, getDefaultOutputCoder, getKindString, getName, getResourceHints, populateDisplayData, setResourceHints, toString, validate, validate
public CreateTables(BigQueryIO.Write.CreateDisposition createDisposition, DynamicDestinations<?,DestinationT> dynamicDestinations)
TODO: We should put a bound on memory usage of this. Use guava cache instead.
public PCollection<KV<TableDestination,ElementT>> expand(PCollection<KV<DestinationT,ElementT>> input)
PTransform
PTransform
should be expanded on the given
InputT
.
NOTE: This method should not be called directly. Instead apply the PTransform
should
be applied to the InputT
using the apply
method.
Composite transforms, which are defined in terms of other transforms, should return the output of one of the composed transforms. Non-composite transforms, which do not apply any transforms internally, should return a new unbound output and register evaluators (via backend-specific registration methods).
expand
in class PTransform<PCollection<KV<DestinationT,ElementT>>,PCollection<KV<TableDestination,ElementT>>>