aokolnychyi commented on a change in pull request #33008: URL: https://github.com/apache/spark/pull/33008#discussion_r658351718
########## File path: sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/analysis/RewriteDeleteFromTable.scala ########## @@ -0,0 +1,186 @@ +/* + * Licensed to the Apache Software Foundation (ASF) under one or more + * contributor license agreements. See the NOTICE file distributed with + * this work for additional information regarding copyright ownership. + * The ASF licenses this file to You under the Apache License, Version 2.0 + * (the "License"); you may not use this file except in compliance with + * the License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +package org.apache.spark.sql.catalyst.analysis + +import java.util.UUID + +import org.apache.spark.sql.AnalysisException +import org.apache.spark.sql.catalyst.InternalRowProjection +import org.apache.spark.sql.catalyst.analysis.RowDeltaUtils._ +import org.apache.spark.sql.catalyst.expressions.{Alias, AttributeReference, EqualNullSafe, Expression, Literal, Not} +import org.apache.spark.sql.catalyst.plans.logical.{DeleteFromTable, Filter, LogicalPlan, Project, ReplaceData, WriteDelta} +import org.apache.spark.sql.catalyst.rules.Rule +import org.apache.spark.sql.connector.catalog.{SupportsDelete, SupportsRowLevelOperations} +import org.apache.spark.sql.connector.expressions.{FieldReference, NamedReference} +import org.apache.spark.sql.connector.write.{LogicalWriteInfo, LogicalWriteInfoImpl, RowLevelOperation, RowLevelOperationTable, SupportsDelta} +import org.apache.spark.sql.connector.write.RowLevelOperation.Command.DELETE +import org.apache.spark.sql.execution.datasources.v2.DataSourceV2Relation +import org.apache.spark.sql.types.{BooleanType, StructType} +import org.apache.spark.sql.util.CaseInsensitiveStringMap + +/** + * Assigns a rewrite plan for v2 tables that support rewriting data to handle DELETE statements. + * + * If a table implements [[SupportsDelete]] and [[SupportsRowLevelOperations]], we assign a rewrite + * plan but the optimizer will check whether this particular DELETE statement can be handled + * by simply passing delete filters to the connector. If yes, the optimizer will then discard + * the rewrite plan. + */ +object RewriteDeleteFromTable extends Rule[LogicalPlan] { + + override def apply(plan: LogicalPlan): LogicalPlan = plan resolveOperators { + case delete @ DeleteFromTable(aliasedTable, cond, None) if delete.resolved => + EliminateSubqueryAliases(aliasedTable) match { + case relation @ DataSourceV2Relation(table: SupportsRowLevelOperations, _, _, _, _) => + val rowLevelOperation = buildRowLevelOperation(table) + val rowLevelOperationTable = RowLevelOperationTable(table, rowLevelOperation) + val rewritePlan = rowLevelOperation match { + case _: SupportsDelta => buildWriteDeltaPlan(relation, rowLevelOperationTable, cond) + case _ => buildReplaceDataPlan(relation, rowLevelOperationTable, cond) + } + // keep the original relation in DELETE so that we can attempt to delete with metadata + DeleteFromTable(relation, cond, Some(rewritePlan)) + + case DataSourceV2Relation(_: SupportsDelete, _, _, _, _) => + // don't assign a rewrite plan as the table supports deletes only with filters + delete + + case DataSourceV2Relation(t, _, _, _, _) => + throw new AnalysisException(s"Table $t does not support DELETE statements") + + case _ => + delete + } + } + + // build a rewrite plan for sources that support replacing groups of data (e.g. files, partitions) + private def buildReplaceDataPlan( + relation: DataSourceV2Relation, + table: RowLevelOperationTable, + cond: Option[Expression]): LogicalPlan = { + + // resolve all columns needed for DELETE including metadata columns for grouping data on write + val requiredWriteAttrs = resolveRefs(relation, table.operation.requiredWriteAttributes) + + // construct a scan relation + val scanAttrs = toScanAttrs(relation, requiredWriteAttrs) + val scanRelation = relation.copy(table = table, output = scanAttrs) + + // construct a plan that contains unmatched rows in matched groups that must be carried over + // such rows do not match the condition but have to be copied over as the source can replace + // only groups of rows + val deleteCond = cond.getOrElse(Literal.TrueLiteral) + val remainingRowsFilter = Not(EqualNullSafe(deleteCond, Literal(true, BooleanType))) + val remainingRowsPlan = Filter(remainingRowsFilter, scanRelation) + + // pass only required columns for unmatched rows to the writer + val writeRelation = relation.copy(table = table, output = requiredWriteAttrs) + ReplaceData(writeRelation, remainingRowsPlan, relation) + } + + // build a rewrite plan for sources that support row-level changes + private def buildWriteDeltaPlan( + relation: DataSourceV2Relation, + table: RowLevelOperationTable, + cond: Option[Expression]): LogicalPlan = { + + val merge = table.operation.asInstanceOf[SupportsDelta] + + // resolve all columns needed for merge (e.g. row ID and columns for grouping data on write) + val requiredWriteAttrs = resolveRefs(relation, table.operation.requiredWriteAttributes) + val rowIdAttrs = resolveRefs(relation, merge.rowId) + + // construct a scan relation and include all required columns + val scanAttrs = toScanAttrs(relation, requiredWriteAttrs) + val scanRelation = relation.copy(table = table, output = scanAttrs) + + // construct a plan that only contains records to delete + val deleteCond = cond.getOrElse(Literal.TrueLiteral) + val deletedRowsPlan = Filter(deleteCond, scanRelation) + val operation = Alias(Literal(DELETE_OPERATION), OPERATION_COLUMN)() + val project = Project(operation +: requiredWriteAttrs, deletedRowsPlan) + + // pass operation and required columns to the writer as we are working with deltas + val operationAttr = resolveRef(project, FieldReference(OPERATION_COLUMN)) Review comment: This part is a bit ugly as we have an extra column that I currently make part of relation output so that the default name-based resolution works. An alternative is to add references to `WriteDelta` and have some custom resolution logic. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
