exec/java-exec/src/main/java/org/apache/drill/exec/physical/base/DbGroupScan.java

/*
 * 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.drill.exec.physical.base;

import org.apache.calcite.rel.RelNode;
import org.apache.drill.common.expression.FieldReference;
import org.apache.calcite.rex.RexNode;
import org.apache.drill.common.expression.SchemaPath;
import org.apache.drill.exec.planner.index.IndexCollection;
import com.fasterxml.jackson.annotation.JsonIgnore;
import org.apache.drill.exec.planner.cost.PluginCost;
import org.apache.drill.exec.planner.physical.PartitionFunction;
import org.apache.drill.exec.planner.index.Statistics;

import java.util.List;

/**
 * A DbGroupScan operator represents the scan associated with a database. The underlying
 * database may support secondary indexes, so there are interface methods for indexes.
 */
public interface DbGroupScan extends GroupScan {


  @JsonIgnore
  boolean supportsSecondaryIndex();

  /**
   * Get the index collection associated with this table if any
   */
  @JsonIgnore
  IndexCollection getSecondaryIndexCollection(RelNode scan);

  /**
   * Set the artificial row count after applying the {@link RexNode} condition
   *
   * @param condition row expression
   * @param count right index row count
   * @param capRowCount row count limit
   */
  @JsonIgnore
  void setRowCount(RexNode condition, double count, double capRowCount);

  /**
   * Get the row count after applying the {@link RexNode} condition
   *
   * @param condition filter to apply
   * @param scanRel the current scan rel
   * @return row count post filtering
   */
  @JsonIgnore
  double getRowCount(RexNode condition, RelNode scanRel);

  /**
   * Get the statistics for this {@link DbGroupScan}
   *
   * @return the {@link Statistics} for this Scan
   */
  @JsonIgnore
  Statistics getStatistics();

  List<SchemaPath> getColumns();

  void setCostFactor(double sel);

  @JsonIgnore
  boolean isIndexScan();

  /**
   * Whether this DbGroupScan supports creating a restricted (skip) scan
   *
   * @return true if restricted scan is supported, false otherwise
   */
  @JsonIgnore
  boolean supportsRestrictedScan();

  /**
   * Whether this DbGroupScan is itself a restricted scan
   *
   * @return true if this DbGroupScan is itself a restricted scan, false otherwise
   */
  @JsonIgnore
  boolean isRestrictedScan();

  /**
   * If this DbGroupScan supports restricted scan, create a restricted scan from this DbGroupScan.
   *
   * @param columns list of column paths
   * @return a non-null DbGroupScan if restricted scan is supported, null otherwise
   */
  @JsonIgnore
  DbGroupScan getRestrictedScan(List<SchemaPath> columns);

  @JsonIgnore
  String getRowKeyName();

  @JsonIgnore
  String getIndexHint();

  @JsonIgnore
  SchemaPath getRowKeyPath();

  /**
   * Get a partition function instance for range based partitioning
   *
   * @param refList a list of FieldReference exprs that are participating in the range partitioning
   * @return instance of a partitioning function
   */
  @JsonIgnore
  PartitionFunction getRangePartitionFunction(List<FieldReference> refList);

  /**
   * Get the format plugin cost model. The cost model will provide cost factors such as seq. scan cost,
   * random scan cost, block size
   *
   * @return a PluginCost cost model
   */
  @JsonIgnore
  PluginCost getPluginCostModel();

  @JsonIgnore
  boolean isFilterPushedDown();
}