| Interface | Description | 
|---|---|
| QueryExecutionListener | The interface of query execution listener that can be used to analyze execution metrics. | 
| Class | Description | 
|---|---|
| ArrowUtils | |
| CaseInsensitiveStringMap | Case-insensitive map of string keys to string values. | 
| ExecutionListenerManager | Manager for  QueryExecutionListener. | 
| MapperRowCounter | An AccumulatorV2 counter for collecting a list of (mapper index, row count). | 
| NumericHistogram | A generic, re-usable histogram class that supports partial aggregations. | 
| NumericHistogram.Coord | The Coord class defines a histogram bin, which is just an (x,y) pair. | 
| PartitioningUtils | |
| SchemaUtils | Utils for handling schemas. | 
| SQLOpenHashSet<T> |