Module com.darkcollective.relix.ast

Package com.darkcollective.relix.ast

Record Class PivotNode

java.lang.Object

java.lang.Record

com.darkcollective.relix.ast.PivotNode

Record Components:

valueColumn - the column whose values fill the new pivot cells; must not be blank

keyColumn - the column whose distinct values become new column headers; must not be blank

groupKeys - the PER grouping columns; empty means one global group; must not be null

input - the source relation; must not be null

location - the source location of this node; never null

All Implemented Interfaces:

RelNode

public record PivotNode(String valueColumn, String keyColumn, List<String> groupKeys, RelNode input, SourceLocation location)
extends Record
implements RelNode

Row-pivoting operator (PIVOT) — spreads distinct values of a key column into new columns.

The PIVOT operator groups rows by the optional groupKeys() (or treats the whole relation as one group when groupKeys() is empty), finds the distinct values of keyColumn(), and emits one output row per group. Each distinct key value becomes a new column whose cell value is taken from valueColumn().

Because the output schema depends on the runtime data (the distinct key values are not known at parse time), PIVOT always produces an open, schema-on-read Schema.open() as its output schema. Column names in the output are the string representations of the distinct key values.

Surface syntax:

   PIVOT revenue BY month PER region (MonthlySales)
   PIVOT amount BY category (Transactions)
 

PIVOT is a blocking operator (MaterializationMode.BAG) — it must consume the entire input before it can emit any output, since it needs to discover the full set of distinct key values first. It is never pushed down to a source.

Constructor Summary

Constructors

Constructor	Description
PivotNode(String valueColumn, String keyColumn, List<String> groupKeys, RelNode input)	Convenience constructor for tests: SourceLocation.UNKNOWN.
PivotNode(String valueColumn, String keyColumn, List<String> groupKeys, RelNode input, SourceLocation location)	Creates an instance of a PivotNode 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.
List<String>	groupKeys()	Returns the value of the groupKeys record component.
final int	hashCode()	Returns a hash code value for this object.
RelNode	input()	Returns the value of the input record component.
String	keyColumn()	Returns the value of the keyColumn record component.
SourceLocation	location()	Returns the value of the location 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

PivotNode

public PivotNode(String valueColumn,
 String keyColumn,
 List<String> groupKeys,
 RelNode input,
 SourceLocation location)

Creates an instance of a PivotNode record class.

Parameters:

valueColumn - the value for the valueColumn record component

keyColumn - the value for the keyColumn record component

groupKeys - the value for the groupKeys record component

input - the value for the input record component

location - the value for the location record component

PivotNode

public PivotNode(String valueColumn,
 String keyColumn,
 List<String> groupKeys,
 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.

valueColumn

public String valueColumn()

Returns the value of the valueColumn record component.

Returns:

the value of the valueColumn record component

keyColumn

public String keyColumn()

Returns the value of the keyColumn record component.

Returns:

the value of the keyColumn record component

groupKeys

public List<String> groupKeys()

Returns the value of the groupKeys record component.

Returns:

the value of the groupKeys 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