ExpressionPlanner (druid-processing 32.0.0 API)

java.lang.Object
- org.apache.druid.segment.virtual.ExpressionPlanner

public class ExpressionPlanner
extends Object

Method Summary

All Methods Static Methods Concrete Methods
Modifier and Type	Method	Description
`static ExpressionPlan`	`plan(ColumnInspector inspector, Expr expression)`	Druid tries to be chill to expressions to make up for not having a well defined table schema across segments.

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

- Method Detail
  - plan
```
public static ExpressionPlan plan(ColumnInspector inspector,
                                  Expr expression)
```
    Druid tries to be chill to expressions to make up for not having a well defined table schema across segments. This method performs some analysis to determine what sort of selectors can be constructed on top of an expression, whether or not the expression will need implicitly mapped across multi-valued inputs, if the expression produces multi-valued outputs, is vectorizable, and everything else interesting when making a selector. Results are stored in a ExpressionPlan, which can be examined to do whatever is necessary to make things function properly.