blerer commented on code in PR #3095: URL: https://github.com/apache/cassandra/pull/3095#discussion_r1567428883
########## src/java/org/apache/cassandra/cql3/restrictions/ClusteringElements.java: ########## @@ -0,0 +1,449 @@ +/* + * 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.cql3.restrictions; + +import java.nio.ByteBuffer; +import java.util.List; + +import com.google.common.collect.BoundType; +import com.google.common.collect.ForwardingList; +import com.google.common.collect.ImmutableList; +import com.google.common.collect.Range; +import com.google.common.collect.RangeSet; +import com.google.common.collect.TreeRangeSet; + +import org.apache.cassandra.cql3.ColumnSpecification; +import org.apache.cassandra.db.BufferClusteringBound; +import org.apache.cassandra.db.ClusteringBound; +import org.apache.cassandra.db.marshal.AbstractType; +import org.apache.cassandra.schema.ColumnMetadata; + +/** + * One or more contiguous clusterings elements. A clustering element is composed of a clustering column and its + * associated value. In practice, that class is not only used for clustering elements but also for partition key elements + * and tokens expression. + * + * <p>There are some difference between how predicates are represented in a CQL query and how they have to be expressed + * internally. Those differences are: + * <ul> + * <li>The selected partition keys and clustering columns can be expressed with separates predicates in a CQL query + * but need to be grouped internally to define exact partition and clustering keys. For example, + * <pre>[..] WHERE pk1 = 2 AND pk2 = 3 AND c1 = 5 AND c2 IN (3, 4)</pre> will request 2 rows with clustering (5, 3) and + * (5, 4) from the partition (2, 3).</li> + * <li>When clustering slices are expressed in a CQL query they are expressed as if all columns were in + * ascending order. Internally the engine handle slice according to the clustering columns real order. + * For example, if column c1 is descending and column c2 is ascending the predicate <pre>(c1, c2) >= (1, 2)</pre> + * should be translated internally in [(bottom) .. (1, bottom)),[(1, 2, bottom)..(1.top)].</li> Review Comment: Not sure about this one. The bottom should stay, no? -- 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]
