org.neo4j.cypher.internal.logical.plans.Aggregation.scala Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of neo4j-cypher-logical-plans Show documentation

Cypher logical plans

There is a newer version: 5.25.1

Show newest version

/*
 * Copyright (c) "Neo4j"
 * Neo4j Sweden AB [http://neo4j.com]
 *
 * This file is part of Neo4j.
 *
 * Neo4j is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see .
 */
package org.neo4j.cypher.internal.logical.plans

import org.neo4j.cypher.internal.expressions.Expression
import org.neo4j.cypher.internal.util.attribution.IdGen

/**
 * Aggregation is a more advanced version of Distinct, where source rows are grouped by the
 * values of the groupingsExpressions. When the source is fully consumed, one row is produced
 * for every group, containing the values of the groupingExpressions for that row, as well as
 * aggregates computed on all the rows in that group.
 *
 * If there are no groupingExpressions, aggregates are computed over all source rows.
 */
case class Aggregation(override val source: LogicalPlan,
                       override val groupingExpressions: Map[String, Expression],
                       override val aggregationExpressions: Map[String, Expression])
                      (implicit idGen: IdGen)
  extends LogicalUnaryPlan(idGen) with EagerLogicalPlan with AggregatingPlan with ProjectingPlan {

 override def withLhs(newLHS: LogicalPlan)(idGen: IdGen): LogicalUnaryPlan = copy(source = newLHS)(idGen)

  override def addGroupingExpressions(newGroupingExpressions: Map[String, Expression]): AggregatingPlan =
    copy(groupingExpressions = groupingExpressions ++ newGroupingExpressions)

 override val projectExpressions: Map[String, Expression] = groupingExpressions

 val groupingKeys: Set[String] = groupingExpressions.keySet

  val availableSymbols: Set[String] = groupingKeys ++ aggregationExpressions.keySet

}