org.apache.calcite.plan

Enum DeriveMode

java.lang.Object

java.lang.Enum<DeriveMode>

org.apache.calcite.plan.DeriveMode

All Implemented Interfaces:

Serializable, Comparable<DeriveMode>

public enum DeriveMode
extends Enum<DeriveMode>

The mode of trait derivation.

Enum Constant Summary

Enum Constants

Enum Constant and Description
BOTH Iterates over each child, uses current child's traits to decide what traits to require from the other children.
LEFT_FIRST Uses the left most child's traits to decide what traits to require from the other children.
OMAKASE Leave it to you, you decide what you cook.
PROHIBITED Trait derivation is prohibited.
RIGHT_FIRST Uses the right most child's traits to decide what traits to require from the other children.

Method Summary

Modifier and Type	Method and Description
static DeriveMode	valueOf(String name) Returns the enum constant of this type with the specified name.
static DeriveMode[]	values() Returns an array containing the constants of this enum type, in the order they are declared.

Methods inherited from class java.lang.Enum

clone, compareTo, equals, finalize, getDeclaringClass, hashCode, name, ordinal, toString, valueOf

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Enum Constant Detail

LEFT_FIRST

public static final DeriveMode LEFT_FIRST

Uses the left most child's traits to decide what traits to require from the other children. This generally applies to most operators.

RIGHT_FIRST

public static final DeriveMode RIGHT_FIRST

Uses the right most child's traits to decide what traits to require from the other children. Operators like index nested loop join may find this useful.

BOTH

public static final DeriveMode BOTH

Iterates over each child, uses current child's traits to decide what traits to require from the other children. It includes both LEFT_FIRST and RIGHT_FIRST. System that doesn't enable join commutativity should consider this option. Special customized operators like a Join who has 3 inputs may find this useful too.

OMAKASE

public static final DeriveMode OMAKASE

Leave it to you, you decide what you cook. This will allow planner to pass all the traits from all the children, the user decides how to make use of these traits and whether to derive new rel nodes.

PROHIBITED

public static final DeriveMode PROHIBITED

Trait derivation is prohibited.

Method Detail

values

public static DeriveMode[] values()

Returns an array containing the constants of this enum type, in the order they are declared. This method may be used to iterate over the constants as follows:

for (DeriveMode c : DeriveMode.values())
    System.out.println(c);

Returns:

an array containing the constants of this enum type, in the order they are declared

valueOf

public static DeriveMode valueOf(String name)

Returns the enum constant of this type with the specified name. The string must match exactly an identifier used to declare an enum constant in this type. (Extraneous whitespace characters are not permitted.)

Parameters:

name - the name of the enum constant to be returned.

Returns:

the enum constant with the specified name

Throws:

IllegalArgumentException - if this enum type has no constant with the specified name

NullPointerException - if the argument is null