Package io.trino.plugin.hive

Class HiveApplyProjectionUtil

java.lang.Object

io.trino.plugin.hive.HiveApplyProjectionUtil

public final class HiveApplyProjectionUtil
extends Object

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	HiveApplyProjectionUtil.ProjectedColumnRepresentation

Method Summary

Modifier and Type	Method	Description
static HiveApplyProjectionUtil.ProjectedColumnRepresentation	createProjectedColumnRepresentation(ConnectorExpression expression)
static List<ConnectorExpression>	extractSupportedProjectedColumns(ConnectorExpression expression)
static Optional<String>	find(Map<String,ColumnHandle> assignments, HiveApplyProjectionUtil.ProjectedColumnRepresentation projectedColumn)	Returns the assignment key corresponding to the column represented by {@param projectedColumn} in the {@param assignments}, if one exists.
static ConnectorExpression	replaceWithNewVariables(ConnectorExpression expression, Map<ConnectorExpression,Variable> expressionToVariableMappings)	Replace all connector expressions with variables as given by {@param expressionToVariableMappings} in a top down manner.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

extractSupportedProjectedColumns

public static List<ConnectorExpression> extractSupportedProjectedColumns(ConnectorExpression expression)

createProjectedColumnRepresentation

public static HiveApplyProjectionUtil.ProjectedColumnRepresentation createProjectedColumnRepresentation(ConnectorExpression expression)

replaceWithNewVariables

public static ConnectorExpression replaceWithNewVariables(ConnectorExpression expression,
                                                          Map<ConnectorExpression,Variable> expressionToVariableMappings)

Replace all connector expressions with variables as given by {@param expressionToVariableMappings} in a top down manner. i.e. if the replacement occurs for the parent, the children will not be visited.

find

public static Optional<String> find(Map<String,ColumnHandle> assignments,
                                    HiveApplyProjectionUtil.ProjectedColumnRepresentation projectedColumn)

Returns the assignment key corresponding to the column represented by {@param projectedColumn} in the {@param assignments}, if one exists. The variable in the {@param projectedColumn} can itself be a representation of another projected column. For example, say a projected column representation has variable "x" and a dereferenceIndices=[0]. "x" can in-turn map to a projected column handle with base="a" and [1, 2] as dereference indices. Then the method searches for a column handle in {@param assignments} with base="a" and dereferenceIndices=[1, 2, 0].