DeterminePartitionsJob (druid-indexing-hadoop 28.0.1 API)

java.lang.Object
- org.apache.druid.indexer.DeterminePartitionsJob

All Implemented Interfaces:

org.apache.druid.indexer.Jobby
```
public class DeterminePartitionsJob
extends Object
implements org.apache.druid.indexer.Jobby
```
Determines appropriate ShardSpecs for a job by determining whether or not partitioning is necessary, and if so, choosing the best dimension that satisfies the criteria:
- Must have exactly one value per row.
- Must not generate oversized partitions. A dimension with N rows having the same value will necessarily put all those rows in the same partition, and that partition may be much larger than the target size.
"Best" means a very high cardinality dimension, or, if none exist, the dimension that minimizes variation of segment size relative to the target.

Nested Class Summary

Nested Classes
Modifier and Type	Class	Description
`static class`	`DeterminePartitionsJob.DeterminePartitionsDimSelectionAssumeGroupedMapper`	This DimSelection mapper runs on raw input data that we assume has already been grouped.
`static class`	`DeterminePartitionsJob.DeterminePartitionsDimSelectionCombiner`
`static class`	`DeterminePartitionsJob.DeterminePartitionsDimSelectionOutputFormat`
`static class`	`DeterminePartitionsJob.DeterminePartitionsDimSelectionPartitioner`
`static class`	`DeterminePartitionsJob.DeterminePartitionsDimSelectionPostGroupByMapper`	This DimSelection mapper runs on data generated by our GroupBy job.
`static class`	`DeterminePartitionsJob.DeterminePartitionsDimSelectionReducer`
`static class`	`DeterminePartitionsJob.DeterminePartitionsGroupByMapper`
`static class`	`DeterminePartitionsJob.DeterminePartitionsGroupByReducer`
`static class`	`DeterminePartitionsJob.DimValueCount`

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type Method Description

String getErrorMessage()

Map<String,Object> getStats()

boolean run()
- Methods inherited from class java.lang.Object
  clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Method Detail
  - run
```
public boolean run()
```
    Specified by:
    
    run in interface org.apache.druid.indexer.Jobby
  - getStats
```
public Map<String,Object> getStats()
```
    Specified by:
    
    getStats in interface org.apache.druid.indexer.Jobby
  - getErrorMessage
```
@Nullable
public String getErrorMessage()
```
    Specified by:
    
    getErrorMessage in interface org.apache.druid.indexer.Jobby