zstan commented on code in PR #13464: URL: https://github.com/apache/ignite/pull/13464#discussion_r3801581225
########## modules/calcite/src/main/java/org/apache/ignite/internal/processors/query/calcite/metadata/IgniteMdMinRowCount.java: ########## @@ -0,0 +1,75 @@ +/* + * 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.ignite.internal.processors.query.calcite.metadata; + +import org.apache.calcite.adapter.enumerable.EnumerableLimit; +import org.apache.calcite.rel.core.Sort; +import org.apache.calcite.rel.metadata.ReflectiveRelMetadataProvider; +import org.apache.calcite.rel.metadata.RelMdMinRowCount; +import org.apache.calcite.rel.metadata.RelMetadataProvider; +import org.apache.calcite.rel.metadata.RelMetadataQuery; +import org.apache.calcite.util.BuiltInMethod; + +import static org.apache.calcite.rel.metadata.RelMdUtil.literalValueApproximatedByDouble; + +/** Minimum row count metadata compatible with expression-based FETCH and OFFSET. */ +// TODO: https://issues.apache.org/jira/browse/CALCITE-7592 +// Remove this class and its registration in IgniteMetadata after upgrading to Calcite 1.43. +@SuppressWarnings("unused") // Actually all methods are used by runtime generated classes. +public class IgniteMdMinRowCount extends RelMdMinRowCount { + /** Metadata provider. */ + public static final RelMetadataProvider SOURCE = + ReflectiveRelMetadataProvider.reflectiveSource( + BuiltInMethod.MIN_ROW_COUNT.method, new IgniteMdMinRowCount()); + + /** {@inheritDoc} */ + @Override public Double getMinRowCount(Sort rel, RelMetadataQuery mq) { + Double rowCnt = mq.getMinRowCount(rel.getInput()); + + if (rowCnt == null) + rowCnt = 0D; + + double offset = literalValueApproximatedByDouble(rel.offset, + rel.offset == null ? 0D : rowCnt); + + rowCnt = Math.max(rowCnt - offset, 0D); + + double limit = literalValueApproximatedByDouble(rel.fetch, + rel.fetch == null ? rowCnt : 0D); + + return limit < rowCnt ? limit : rowCnt; + } + + /** {@inheritDoc} */ + @Override public Double getMinRowCount(EnumerableLimit rel, RelMetadataQuery mq) { Review Comment: EnumerableLimit - we not play with enumerables !! -- 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. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
