RelCollation (Apache Calcite API)

All Superinterfaces:

java.lang.Comparable<RelMultipleTrait>, RelMultipleTrait, RelTrait

All Known Implementing Classes:

RelCollationImpl
```
public interface RelCollation
extends RelMultipleTrait
```
Description of the physical ordering of a relational expression.
An ordering consists of a list of one or more column ordinals and the direction of the ordering.

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method	Description
`java.util.List<RelFieldCollation>`	`getFieldCollations()`	Returns the ordinals and directions of the columns in this ordering.

Methods inherited from interface java.lang.Comparable
compareTo

Methods inherited from interface org.apache.calcite.plan.RelMultipleTrait
isTop

Methods inherited from interface org.apache.calcite.plan.RelTrait
equals, getTraitDef, hashCode, register, satisfies, toString

- Method Detail
  - getFieldCollations
```
java.util.List<RelFieldCollation> getFieldCollations()
```
    Returns the ordinals and directions of the columns in this ordering.