mike-tr-adamson commented on code in PR #2673: URL: https://github.com/apache/cassandra/pull/2673#discussion_r1358486563
########## src/java/org/apache/cassandra/index/sai/disk/v1/segment/SegmentOrdering.java: ########## @@ -0,0 +1,56 @@ +/* + * 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.cassandra.index.sai.disk.v1.segment; + +import java.io.IOException; + +import org.apache.cassandra.db.ReadCommand; +import org.apache.cassandra.db.partitions.PartitionIterator; +import org.apache.cassandra.index.sai.QueryContext; +import org.apache.cassandra.index.sai.iterators.KeyRangeIterator; +import org.apache.cassandra.index.sai.plan.Expression; +import org.apache.cassandra.index.sai.postings.PeekablePostingList; + +/** + * There are two steps in ordering: Review Comment: Which bit is outdated? The first block is the same as on the vsearch branch. The second block we added to try and document the second step. ########## src/java/org/apache/cassandra/index/sai/disk/v1/segment/SegmentOrdering.java: ########## @@ -0,0 +1,56 @@ +/* + * 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.cassandra.index.sai.disk.v1.segment; + +import java.io.IOException; + +import org.apache.cassandra.db.ReadCommand; +import org.apache.cassandra.db.partitions.PartitionIterator; +import org.apache.cassandra.index.sai.QueryContext; +import org.apache.cassandra.index.sai.iterators.KeyRangeIterator; +import org.apache.cassandra.index.sai.plan.Expression; +import org.apache.cassandra.index.sai.postings.PeekablePostingList; + +/** + * There are two steps in ordering: + * <p> + * 1. Limit a single sstable's results to the correct keys. At this stage + * we put them back in primary key order to play nice with the rest of + * the query pipeline. + * 2. Merge the results from multiple sstables. Now we leave them in the + * final, correct order. + * <p> + * SegmentOrdering handles the first step. + * + * The second step is handled during post-reconciliation processing when the + * {@link org.apache.cassandra.index.Index.QueryPlan#postProcessor(ReadCommand)} is called by + * {@link org.apache.cassandra.db.PartitionRangeReadCommand#postReconciliationProcessing(PartitionIterator)}. If the + * {@link org.apache.cassandra.index.Index.QueryPlan} is for a topK query then a reordering filter is returned to return + * the partitions in the correct order. + */ +public interface SegmentOrdering +{ + /** + * Reorder, limit, and put back into original order the results from a single sstable Review Comment: As above. -- 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] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
