timoninmaxim commented on a change in pull request #8490: URL: https://github.com/apache/ignite/pull/8490#discussion_r586618568
########## File path: modules/core/src/main/java/org/apache/ignite/internal/cache/query/index/sorted/IndexValueCursor.java ########## @@ -0,0 +1,67 @@ +/* + * 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.cache.query.index.sorted; + +import java.util.function.Function; +import org.apache.ignite.IgniteCheckedException; +import org.apache.ignite.internal.cache.query.index.sorted.inline.io.IndexSearchRow; +import org.apache.ignite.internal.util.lang.GridCursor; + +/** + * Cursor over index values. + * + * @param <V> class represents of value stored in an index. + */ +public class IndexValueCursor<V> implements GridCursor<V> { + /** + * Empty cursor implementation. + */ + public static final GridCursor EMPTY = new GridCursor() { + /** {@inheritDoc} */ + @Override public boolean next() { + return false; + } + + /** {@inheritDoc} */ + @Override public Object get() { + return null; Review comment: Unfortunately I can't fix this. H2Cursor for queries like "select MAX(col) from table" relies on this null. The same issue with SingleCursor. I can add comment there, and create a ticket to have this in mind for Calcite integration. WDYT? ---------------------------------------------------------------- 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]
