Module com.darkcollective.relix.ast

Package com.darkcollective.relix.ast

Record Class LateralJoinNode

java.lang.Object

java.lang.Record

com.darkcollective.relix.ast.LateralJoinNode

Record Components:

left - the outer (driving) relation; must not be null

right - the relation evaluated per left row: a RelationFunctionCall or any relation expression; must not be null

kind - whether a left row with no right rows is dropped or kept; must not be null

location - source location of the LATERAL keyword

All Implemented Interfaces:

RelNode

public record LateralJoinNode(RelNode left, RelNode right, LateralKind kind, SourceLocation location)
extends Record
implements RelNode

A lateral join: its right side is evaluated once per row of its left input, and may read that row's columns.

Two forms are written. left LATERAL fn(arg, …) calls a table-valued function whose arguments may name left columns; the right side is then a RelationFunctionCall. left LATERAL (expression) evaluates a relation expression in which a qualified name whose relation the expression does not read, Customers.customer_id, is a column of the left row. Each left row is joined to the rows its right side yields; OUTER also keeps, once, a left row for which the right side yields none, its right columns NULL.

Both inputs are children: a traversal sees the function call or the expression as it sees any other input. What sets the right side apart is only that it may read the left row, so it is analysed and run in the left row's scope.

Constructor Summary

Constructors

Constructor	Description
LateralJoinNode(RelNode left, RelNode right)	Convenience constructor for tests: an inner lateral; uses SourceLocation.UNKNOWN.
LateralJoinNode(RelNode left, RelNode right, LateralKind kind, SourceLocation location)	Creates an instance of a LateralJoinNode record class.

Method Summary

Modifier and Type	Method	Description
<R> R	accept(RelNodeVisitor<R> visitor)
final boolean	equals(Object o)	Indicates whether some other object is "equal to" this one.
final int	hashCode()	Returns a hash code value for this object.
boolean	isFunctionCall()	Whether the right side is a table-valued function call, L LATERAL fn(…), rather than a relation expression in parentheses.
LateralKind	kind()	Returns the value of the kind record component.
RelNode	left()	Returns the value of the left record component.
SourceLocation	location()	Returns the value of the location record component.
RelNode	right()	Returns the value of the right record component.
final String	toString()	Returns a string representation of this record class.

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface com.darkcollective.relix.ast.RelNode

children, mapChildren, materializationMode, prettyPrint, prettyPrint

Constructor Details

LateralJoinNode

public LateralJoinNode(RelNode left,
 RelNode right,
 LateralKind kind,
 SourceLocation location)

Creates an instance of a LateralJoinNode record class.

Parameters:

left - the value for the left record component

right - the value for the right record component

kind - the value for the kind record component

location - the value for the location record component

LateralJoinNode

public LateralJoinNode(RelNode left,
 RelNode right)

Convenience constructor for tests: an inner lateral; uses SourceLocation.UNKNOWN.

Method Details

isFunctionCall

public boolean isFunctionCall()

Whether the right side is a table-valued function call, L LATERAL fn(…), rather than a relation expression in parentheses.

Returns:

true for the function form

accept

public <R> R accept(RelNodeVisitor<R> visitor)

Specified by:

accept in interface RelNode

toString

public final String toString()

Returns a string representation of this record class. The representation contains the name of the class, followed by the name and value of each of the record components.

Specified by:

toString in class Record

Returns:

a string representation of this object

hashCode

public final int hashCode()

Returns a hash code value for this object. The value is derived from the hash code of each of the record components.

Specified by:

hashCode in class Record

Returns:

a hash code value for this object

equals

public final boolean equals(Object o)

Indicates whether some other object is "equal to" this one. The objects are equal if the other object is of the same class and if all the record components are equal. All components in this record class are compared with Objects::equals(Object,Object).

Specified by:

equals in class Record

Parameters:

o - the object with which to compare

Returns:

true if this object is the same as the o argument; false otherwise.

left

public RelNode left()

Returns the value of the left record component.

Returns:

the value of the left record component

right

public RelNode right()

Returns the value of the right record component.

Returns:

the value of the right record component

kind

public LateralKind kind()

Returns the value of the kind record component.

Returns:

the value of the kind record component

location

public SourceLocation location()

Returns the value of the location record component.

Specified by:

location in interface RelNode

Returns:

the value of the location record component