RowBasedIndexBuilder (druid-processing 28.0.1 API)

java.lang.Object
- org.apache.druid.segment.join.table.RowBasedIndexBuilder

```
public class RowBasedIndexBuilder
extends Object
```
Utility class for creating IndexedTable.Index instances. Its main role is to decide which kind of implementation to use.

Constructor Summary

Constructors
Constructor Description

RowBasedIndexBuilder(ColumnType keyType)

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`RowBasedIndexBuilder`	`add(Object key)`	Add a key to the index.
`IndexedTable.Index`	`build()`	Create the index.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - RowBasedIndexBuilder
```
public RowBasedIndexBuilder(ColumnType keyType)
```
- Method Detail
  - add
```
public RowBasedIndexBuilder add(@Nullable
                                Object key)
```
    Add a key to the index. This must be called exactly once per row, even for null values or values that are the wrong type, because the builder keeps an internal row-number counter. The builder will handle both nulls and mismatched types, so callers do not need to worry about this.
  - build
```
public IndexedTable.Index build()
```
    Create the index. After calling this, the state of the builder is undefined, and you should discard it.