Module com.darkcollective.relix.ast

Package com.darkcollective.relix.ast

Record Class UnpivotNode

java.lang.Object

java.lang.Record

com.darkcollective.relix.ast.UnpivotNode

Record Components:

columns - the ordered list of column names to fold into rows; must not be null or empty

nameColumn - the name of the output column holding the source column name; must not be blank

valueColumn - the name of the output column holding the cell value; must not be blank

input - the source relation; must not be null

location - the source location of this node; never null

All Implemented Interfaces:

RelNode

public record UnpivotNode(List<String> columns, String nameColumn, String valueColumn, RelNode input, SourceLocation location)
extends Record
implements RelNode

Column-folding operator (UNPIVOT) — transforms selected columns into rows.

Given a list of source columns() to fold, UNPIVOT folds each named column into two new columns:

• nameColumn() — a STRING column whose value is the source column name.
• valueColumn() — an ANY column whose value is the cell value from the source column.

For each input row, the operator emits one output row per column in columns(). The output schema is the input schema minus the listed columns, plus nameColumn():STRING and valueColumn():ANY.

Surface syntax:

   UNPIVOT (jan, feb, mar) AS (month, revenue) (MonthlySales)
 

UNPIVOT is a non-blocking, non-collapsing operator — a streaming flatMap that transforms each input row into N output rows where N is the number of columns listed (MaterializationMode.STREAM). It is never pushed down to a source.

Constructor Summary

Constructors

Constructor	Description
UnpivotNode(List<String> columns, String nameColumn, String valueColumn, RelNode input)	Convenience constructor for tests: SourceLocation.UNKNOWN.
UnpivotNode(List<String> columns, String nameColumn, String valueColumn, RelNode input, SourceLocation location)	Creates an instance of a UnpivotNode record class.

Method Summary

Modifier and Type	Method	Description
<R> R	accept(RelNodeVisitor<R> visitor)
List<String>	columns()	Returns the value of the columns record component.
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.
RelNode	input()	Returns the value of the input record component.
SourceLocation	location()	Returns the value of the location record component.
String	nameColumn()	Returns the value of the nameColumn record component.
final String	toString()	Returns a string representation of this record class.
String	valueColumn()	Returns the value of the valueColumn record component.

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

Constructor Details

UnpivotNode

public UnpivotNode(List<String> columns,
 String nameColumn,
 String valueColumn,
 RelNode input,
 SourceLocation location)

Creates an instance of a UnpivotNode record class.

Parameters:

columns - the value for the columns record component

nameColumn - the value for the nameColumn record component

valueColumn - the value for the valueColumn record component

input - the value for the input record component

location - the value for the location record component

UnpivotNode

public UnpivotNode(List<String> columns,
 String nameColumn,
 String valueColumn,
 RelNode input)

Convenience constructor for tests: SourceLocation.UNKNOWN.

Method Details

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.

columns

public List<String> columns()

Returns the value of the columns record component.

Returns:

the value of the columns record component

nameColumn

public String nameColumn()

Returns the value of the nameColumn record component.

Returns:

the value of the nameColumn record component

valueColumn

public String valueColumn()

Returns the value of the valueColumn record component.

Returns:

the value of the valueColumn record component

input

public RelNode input()

Returns the value of the input record component.

Returns:

the value of the input 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