huaxingao commented on code in PR #18776: URL: https://github.com/apache/iceberg/pull/18776#discussion_r4496791177
########## api/src/main/java/org/apache/iceberg/Constraint.java: ########## @@ -0,0 +1,64 @@ +/* + * 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.iceberg; + +import java.io.Serializable; + +/** + * A constraint declares a property that a table's rows are expected to satisfy. + * + * <p>A constraint's definition is stored in table metadata and references the fields it applies to + * by field ID, so it keeps applying after columns are renamed or reordered. The concrete subtype is + * determined by {@link #type()}: a {@link CheckConstraint} carries a predicate, and a {@link + * KeyConstraint} ({@link UniqueConstraint} or {@link PrimaryKeyConstraint}) carries field IDs. + * Iceberg does not evaluate constraints; enforcement and validation are done by engines. Review Comment: Yes. Changed "engines" to "writers". ########## api/src/main/java/org/apache/iceberg/Constraint.java: ########## @@ -0,0 +1,64 @@ +/* + * 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.iceberg; + +import java.io.Serializable; + +/** + * A constraint declares a property that a table's rows are expected to satisfy. + * + * <p>A constraint's definition is stored in table metadata and references the fields it applies to + * by field ID, so it keeps applying after columns are renamed or reordered. The concrete subtype is + * determined by {@link #type()}: a {@link CheckConstraint} carries a predicate, and a {@link + * KeyConstraint} ({@link UniqueConstraint} or {@link PrimaryKeyConstraint}) carries field IDs. + * Iceberg does not evaluate constraints; enforcement and validation are done by engines. + * + * <p>Constraints are supported in format v4 and later. + */ +public interface Constraint extends Serializable { + /** Returns the ID of the constraint, assigned by Iceberg and unique within the table. */ + int id(); + + /** + * Returns the name of the constraint, unique within the table. + * + * <p>Names are for humans and must not be used to identify a constraint in metadata. + */ + String name(); + + /** Returns the constraint {@link ConstraintType type}. */ + ConstraintType type(); + + /** + * Returns whether writers must verify that the rows they add or modify satisfy this constraint. + * + * <p>When enforced, a writer that cannot verify the constraint must reject writes rather than add + * unverified rows. Iceberg core does not enforce constraints. + */ + boolean enforced(); + + /** + * Returns the time the constraint was created or last modified, in milliseconds since the Unix + * epoch. + * + * <p>This value is informational and must not be used to decide whether a constraint applies to a + * snapshot or whether it holds. Review Comment: Yes, it is mainly for audit and debugging, so users can see when a constraint was added or last changed. -- 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]
