content: /*
   * 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.beam.sdk.extensions.sql.meta;
  
  import java.util.List;
  import org.apache.beam.sdk.extensions.sql.impl.BeamTableStatistics;
  import org.apache.beam.sdk.options.PipelineOptions;
  import org.apache.beam.sdk.schemas.Schema;
  import org.apache.beam.sdk.values.PBegin;
  import org.apache.beam.sdk.values.PCollection;
  import org.apache.beam.sdk.values.POutput;
  import org.apache.beam.sdk.values.Row;
  import org.apache.beam.vendor.calcite.v1_40_0.org.apache.calcite.rex.RexNode;
  
  /** This interface defines a Beam Sql Table. */
  public interface BeamSqlTable {
    /** create a {@code PCollection<Row>} from source. */
    PCollection<Row> buildIOReader(PBegin begin);
  
    /** create a {@code PCollection<Row>} from source with predicate and/or project pushed-down. */
    PCollection<Row> buildIOReader(PBegin begin, BeamSqlTableFilter filters, List<String> fieldNames);
  
    /** create a {@code IO.write()} instance to write to target. */
    POutput buildIOWriter(PCollection<Row> input);
  
    /** Generate an IO implementation of {@code BeamSqlTableFilter} for predicate push-down. */
    BeamSqlTableFilter constructFilter(List<RexNode> filter);
  
    /** Whether project push-down is supported by the IO API. */
    ProjectSupport supportsProjects();
  
    /** Whether this table is bounded (known to be finite) or unbounded (may or may not be finite). */
    PCollection.IsBounded isBounded();
  
    /** Get the schema info of the table. */
    Schema getSchema();
  
    /**
     * Estimates the number of rows or the rate for unbounded Tables. If it is not possible to
     * estimate the row count or rate it will return BeamTableStatistics.BOUNDED_UNKNOWN.
     */
    BeamTableStatistics getTableStatistics(PipelineOptions options);
  }
  