FANNG1 commented on code in PR #9678: URL: https://github.com/apache/gravitino/pull/9678#discussion_r2780514318
########## catalogs/catalog-lakehouse-generic/src/main/java/org/apache/gravitino/catalog/lakehouse/delta/DeltaTableDelegator.java: ########## @@ -0,0 +1,76 @@ +/* + * 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.gravitino.catalog.lakehouse.delta; + +import static org.apache.gravitino.catalog.lakehouse.delta.DeltaConstants.DELTA_TABLE_FORMAT; + +import java.util.Collections; +import java.util.List; +import org.apache.gravitino.EntityStore; +import org.apache.gravitino.catalog.ManagedSchemaOperations; +import org.apache.gravitino.catalog.ManagedTableOperations; +import org.apache.gravitino.catalog.lakehouse.generic.LakehouseTableDelegator; +import org.apache.gravitino.connector.PropertyEntry; +import org.apache.gravitino.rel.Table; +import org.apache.gravitino.storage.IdGenerator; + +/** + * Delegator for Delta Lake table format in Gravitino lakehouse catalog. + * + * <p>This delegator provides table operations specific to external Delta Lake tables. It enables + * Gravitino to register and manage metadata for existing Delta tables without creating or modifying + * the underlying Delta table data. + * + * <p>Key features: + * + * <ul> + * <li>Supports external Delta table registration (requires {@code external=true} property) + * <li>Schema is provided by user in CREATE TABLE request (not read from Delta log) + * <li>Uses standard table properties ({@code location}, {@code external}) - no Delta-specific + * properties needed + * <li>Drop operations only remove metadata, preserving the Delta table data + * <li>No ALTER TABLE or PURGE support (external tables should be modified directly) + * </ul> + */ +public class DeltaTableDelegator implements LakehouseTableDelegator { + + @Override + public String tableFormat() { + return DELTA_TABLE_FORMAT; + } + + /** + * Returns Delta-specific table property entries. + * + * <p>Delta tables use standard table properties ({@link Table#PROPERTY_LOCATION} and {@link + * Table#PROPERTY_EXTERNAL}), so no Delta-specific properties are needed. + * + * @return an empty list since all required properties are standard table properties + */ + @Override + public List<PropertyEntry<?>> tablePropertyEntries() { Review Comment: seems PROPERTY_EXTERNAL is not handled in the `GenericTablePropertiesMetadata ` https://github.com/apache/gravitino/blob/cc039f855e9ad4215e16eebe62409d143084510c/catalogs/catalog-lakehouse-generic/src/main/java/org/apache/gravitino/catalog/lakehouse/generic/GenericTablePropertiesMetadata.java#L39-L51 -- 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]
