zabetak commented on a change in pull request #1020: [CALCITE-2812] Add algebraic operators to allow expressing recursive queries (Ruben Quesada Lopez) URL: https://github.com/apache/calcite/pull/1020#discussion_r276228589
########## File path: core/src/main/java/org/apache/calcite/adapter/enumerable/EnumerableTableSpool.java ########## @@ -0,0 +1,104 @@ +/* + * 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.calcite.adapter.enumerable; + +import org.apache.calcite.linq4j.function.Experimental; +import org.apache.calcite.linq4j.tree.BlockBuilder; +import org.apache.calcite.linq4j.tree.Expression; +import org.apache.calcite.linq4j.tree.Expressions; +import org.apache.calcite.plan.RelOptCluster; +import org.apache.calcite.plan.RelTraitSet; +import org.apache.calcite.rel.RelNode; +import org.apache.calcite.rel.RelWriter; +import org.apache.calcite.rel.core.Spool; +import org.apache.calcite.schema.ModifiableTable; +import org.apache.calcite.util.BuiltInMethod; + +/** + * Implementation of {@link Spool} in + * {@link EnumerableConvention enumerable calling convention} + * that writes into a {@link ModifiableTable} + * + * <p>NOTE: The current API is experimental and subject to change without notice.</p> + */ +@Experimental +public class EnumerableTableSpool extends Spool implements EnumerableRel { + + // table name, it must refer to an existing ModifiableTable + protected final String tableName; + + protected EnumerableTableSpool(RelOptCluster cluster, RelTraitSet traitSet, RelNode input, + Type readType, Type writeType, String tableName) { + super(cluster, traitSet, input, readType, writeType); + this.tableName = tableName; + } + + @Override public Result implement(EnumerableRelImplementor implementor, Prefer pref) { + // TODO for the moment only LAZY read & write is supported + if (!(readType == Type.LAZY && writeType == Type.LAZY)) { Review comment: Rewrite as `readType != Type.LAZY || writeType != Type.LAZY`? ---------------------------------------------------------------- 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: us...@infra.apache.org With regards, Apache Git Services
