io.trino.spi.function.table.ConnectorTableFunction Maven / Gradle / Ivy

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/*
 * Licensed 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 io.trino.spi.function.table;

import io.trino.spi.Experimental;
import io.trino.spi.connector.ConnectorAccessControl;
import io.trino.spi.connector.ConnectorSession;
import io.trino.spi.connector.ConnectorTransactionHandle;

import java.util.List;
import java.util.Map;

@Experimental(eta = "2022-10-31")
public interface ConnectorTableFunction
{
    String getSchema();

    String getName();

    List getArguments();

    ReturnTypeSpecification getReturnTypeSpecification();

    /**
     * This method is called by the Analyzer. Its main purposes are to:
     * 1. Determine the resulting relation type of the Table Function in case when the declared return type is GENERIC_TABLE.
     * 2. Declare the required columns from the input tables.
     * 3. Perform function-specific validation and pre-processing of the input arguments.
     * As part of function-specific validation, the Table Function's author might want to:
     * - check if the descriptors which reference input tables contain a correct number of column references
     * - check if the referenced input columns have appropriate types to fit the function's logic // TODO return request for coercions to the Analyzer in the TableFunctionAnalysis object
     * - if there is a descriptor which describes the function's output, check if it matches the shape of the actual function's output
     * - for table arguments, check the number and types of ordering columns
     * 
     * The actual argument values, and the pre-processing results can be stored in an ConnectorTableFunctionHandle
     * object, which will be passed along with the Table Function invocation through subsequent phases of planning.
     *
     * @param arguments actual invocation arguments, mapped by argument names
     */
    TableFunctionAnalysis analyze(ConnectorSession session, ConnectorTransactionHandle transaction, Map arguments, ConnectorAccessControl accessControl);
}