beliefer commented on code in PR #50253: URL: https://github.com/apache/spark/pull/50253#discussion_r2019773251
########## sql/catalyst/src/main/java/org/apache/spark/sql/connector/catalog/constraints/Unique.java: ########## @@ -0,0 +1,102 @@ +/* + * 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.spark.sql.connector.catalog.constraints; + +import java.util.Arrays; +import java.util.Objects; + +import org.apache.spark.sql.connector.expressions.NamedReference; + +/** + * A UNIQUE constraint. + * <p> + * A UNIQUE constraint specifies one or more columns as unique columns. Such constraint is satisfied + * if and only if no two rows in a table have the same non-null values in the unique columns. + * <p> + * Spark doesn't enforce UNIQUE constraints but leverages them for query optimization. Each + * constraint is either valid (the existing data is guaranteed to satisfy the constraint), invalid + * (some records violate the constraint), or unvalidated (the validity is unknown). If the validity + * is unknown, Spark will check {@link #rely()} to see whether the constraint is believed to be + * true and can be used for query optimization. + * + * @since 4.1.0 + */ +public class Unique extends BaseConstraint { + + private final NamedReference[] columns; + + private Unique( + String name, + NamedReference[] columns, + boolean enforced, + ValidationStatus validationStatus, + boolean rely) { + super(name, enforced, validationStatus, rely); Review Comment: ditto. -- 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: reviews-unsubscr...@spark.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: reviews-unsubscr...@spark.apache.org For additional commands, e-mail: reviews-h...@spark.apache.org
