Package org.apache.drill.exec.expr
Class BatchReference
java.lang.Object
org.apache.drill.exec.expr.BatchReference
Holder class that contains batch naming, batch and record index. Batch index is used when batch is hyper container.
Used to distinguish batches in non-equi conditions during expression materialization.
Mostly used for nested loop join which allows non equi-join.
BatchReference instance can be created during batch initialization
(ex: instance of
AbstractRecordBatch
)
since naming of batches used won't change during data processing.
Though information from batch reference will be used during schema build (i.e. once per OK_NEW_SCHEMA).
Example:
BatchReference{batchName='leftBatch', batchIndex='leftIndex', recordIndex='leftIndex'}
BatchReference{batchName='rightContainer', batchIndex='rightBatchIndex', recordIndex='rightRecordIndexWithinBatch'}-
Constructor Summary
ConstructorDescriptionBatchReference
(String batchName, String recordIndex) BatchReference
(String batchName, String batchIndex, String recordIndex) -
Method Summary