/*
 * 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 net.hydromatic.optiq;

import org.eigenbase.reltype.RelDataType;
import org.eigenbase.reltype.RelDataTypeFactory;

/**
 * Table.
 *
 * <p>The typical way for a table to be created is when Calcite interrogates
 * a user-defined schema in order to validate names appearing in a SQL query.
 * Calcite finds the schema by calling {@link Schema#getSubSchema(String)} on the
 * connection's root schema, then gets a table by calling
 * {@link Schema#getTable(String)}.</p>
 *
 * <p>Note that a table does not know its name. It is in fact possible for
 * a table to be used more than once, perhaps under multiple names or under
 * multiple schemas. (Compare with the
 * <a href="http://en.wikipedia.org/wiki/Inode">i-node</a> concept in the UNIX
 * filesystem.)</p>
 *
 * @see TableMacro
 */
public interface Table {
  /** Returns this table's row type.
   *
   * <p>This is a struct type whose
   * fields describe the names and types of the columns in this table.</p>
   *
   * <p>The implementer must use the type factory provided. This ensures that
   * the type is converted into a canonical form; other equal types in the same
   * query will use the same object.</p>
   *
   * @param typeFactory Type factory with which to create the type
   * @return Row type
   */
  RelDataType getRowType(RelDataTypeFactory typeFactory);

  /** Returns a provider of statistics about this table. */
  Statistic getStatistic();

  /** Type of table. */
  Schema.TableType getJdbcTableType();
}

// End Table.java