public class PrepareWrite<T,DestinationT> extends PTransform<PCollection<T>,PCollection<KV<DestinationT,TableRow>>>
PCollection
for writing to BigQuery. Use the table function to determine
which tables each element is written to, and format the element into a TableRow
using the
user-supplied format function.name
Constructor and Description |
---|
PrepareWrite(DynamicDestinations<T,DestinationT> dynamicDestinations,
SerializableFunction<T,TableRow> formatFunction) |
Modifier and Type | Method and Description |
---|---|
PCollection<KV<DestinationT,TableRow>> |
expand(PCollection<T> input)
Override this method to specify how this
PTransform should be expanded
on the given InputT . |
getAdditionalInputs, getDefaultOutputCoder, getDefaultOutputCoder, getDefaultOutputCoder, getKindString, getName, populateDisplayData, toString, validate
public PrepareWrite(DynamicDestinations<T,DestinationT> dynamicDestinations, SerializableFunction<T,TableRow> formatFunction)
public PCollection<KV<DestinationT,TableRow>> expand(PCollection<T> 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<T>,PCollection<KV<DestinationT,TableRow>>>