| /* |
| * 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.store.sys; |
| |
| import java.util.Collection; |
| import java.util.Collections; |
| import java.util.List; |
| |
| import com.fasterxml.jackson.annotation.JacksonInject; |
| import com.fasterxml.jackson.annotation.JsonCreator; |
| import com.fasterxml.jackson.annotation.JsonIgnore; |
| import com.fasterxml.jackson.annotation.JsonProperty; |
| import com.fasterxml.jackson.annotation.JsonTypeName; |
| import org.apache.drill.shaded.guava.com.google.common.collect.Lists; |
| import org.apache.drill.common.exceptions.ExecutionSetupException; |
| import org.apache.drill.common.expression.SchemaPath; |
| import org.apache.drill.exec.physical.EndpointAffinity; |
| import org.apache.drill.exec.physical.base.AbstractGroupScan; |
| import org.apache.drill.exec.physical.base.GroupScan; |
| import org.apache.drill.exec.physical.base.PhysicalOperator; |
| import org.apache.drill.exec.physical.base.ScanStats; |
| import org.apache.drill.exec.physical.base.SubScan; |
| import org.apache.drill.exec.planner.fragment.DistributionAffinity; |
| import org.apache.drill.exec.proto.CoordinationProtos.DrillbitEndpoint; |
| import org.apache.drill.exec.proto.UserBitShared.CoreOperatorType; |
| import org.apache.drill.exec.store.StoragePluginRegistry; |
| |
| @JsonTypeName("sys") |
| public class SystemTableScan extends AbstractGroupScan implements SubScan { |
| |
| private final SystemTable table; |
| private final SystemTablePlugin plugin; |
| private int maxRecordsToRead; |
| |
| @JsonCreator |
| public SystemTableScan(@JsonProperty("table") SystemTable table, |
| @JsonProperty("maxRecordsToRead") int maxRecordsToRead, |
| @JacksonInject StoragePluginRegistry engineRegistry) throws ExecutionSetupException { |
| this(table, maxRecordsToRead, (SystemTablePlugin) engineRegistry.getPlugin(SystemTablePluginConfig.INSTANCE)); |
| } |
| |
| public SystemTableScan(SystemTable table, SystemTablePlugin plugin) { |
| this(table, Integer.MAX_VALUE, plugin); |
| } |
| |
| public SystemTableScan(SystemTable table, int maxRecordsToRead, SystemTablePlugin plugin) { |
| super((String) null); |
| this.table = table; |
| this.maxRecordsToRead = maxRecordsToRead; |
| this.plugin = plugin; |
| } |
| |
| /** |
| * System tables do not need stats. |
| * @return a trivial stats table |
| */ |
| @Override |
| public ScanStats getScanStats() { |
| return ScanStats.TRIVIAL_TABLE; |
| } |
| |
| @Override |
| public PhysicalOperator getNewWithChildren(List<PhysicalOperator> children) { |
| return new SystemTableScan(table, maxRecordsToRead, plugin); |
| } |
| |
| @Override |
| public void applyAssignments(List<DrillbitEndpoint> endpoints) { |
| } |
| |
| @JsonIgnore |
| @Override |
| public List<SchemaPath> getColumns() { |
| return super.getColumns(); |
| } |
| |
| @Override |
| public SubScan getSpecificScan(int minorFragmentId) { |
| return this; |
| } |
| |
| // If distributed, the scan needs to happen on every node. |
| @Override |
| public int getMaxParallelizationWidth() { |
| return table.isDistributed() ? plugin.getContext().getBits().size() : 1; |
| } |
| |
| // If distributed, the scan needs to happen on every node. |
| @Override |
| public int getMinParallelizationWidth() { |
| return table.isDistributed() ? plugin.getContext().getBits().size() : 1; |
| } |
| |
| @Override |
| public long getInitialAllocation() { |
| return initialAllocation; |
| } |
| |
| @Override |
| public long getMaxAllocation() { |
| return maxAllocation; |
| } |
| |
| /** |
| * Example: SystemTableScan [table=OPTION, distributed=false, maxRecordsToRead=1] |
| * |
| * @return string representation of system table scan |
| */ |
| @Override |
| public String getDigest() { |
| StringBuilder builder = new StringBuilder(); |
| builder.append("SystemTableScan ["); |
| builder.append("table=").append(table.name()).append(", "); |
| builder.append("distributed=").append(table.isDistributed()); |
| if (maxRecordsToRead != Integer.MAX_VALUE) { |
| builder.append(", maxRecordsToRead=").append(maxRecordsToRead); |
| } |
| builder.append("]"); |
| |
| return builder.toString(); |
| } |
| |
| @Override |
| public int getOperatorType() { |
| return CoreOperatorType.SYSTEM_TABLE_SCAN_VALUE; |
| } |
| |
| /** |
| * If distributed, the scan needs to happen on every node. Since width is enforced, the number of fragments equals |
| * number of Drillbits. And here we set, each endpoint as mandatory assignment required to ensure every |
| * Drillbit executes a fragment. |
| * @return the Drillbit endpoint affinities |
| */ |
| @Override |
| public List<EndpointAffinity> getOperatorAffinity() { |
| if (table.isDistributed()) { |
| final List<EndpointAffinity> affinities = Lists.newArrayList(); |
| final Collection<DrillbitEndpoint> bits = plugin.getContext().getBits(); |
| final double affinityPerNode = 1d / bits.size(); |
| for (final DrillbitEndpoint endpoint : bits) { |
| affinities.add(new EndpointAffinity(endpoint, affinityPerNode, true, /* maxWidth = */ 1)); |
| } |
| return affinities; |
| } else { |
| return Collections.emptyList(); |
| } |
| } |
| |
| @Override |
| public DistributionAffinity getDistributionAffinity() { |
| return table.isDistributed() ? DistributionAffinity.HARD : DistributionAffinity.SOFT; |
| } |
| |
| @Override |
| public GroupScan clone(List<SchemaPath> columns) { |
| return this; |
| } |
| |
| public GroupScan clone(SystemTableScan systemTableScan, int maxRecordsToRead) { |
| return new SystemTableScan(systemTableScan.getTable(), maxRecordsToRead, systemTableScan.getPlugin()); |
| } |
| |
| @Override |
| public boolean supportsLimitPushdown() { |
| return true; |
| } |
| |
| @Override |
| public GroupScan applyLimit(int maxRecords) { |
| if (maxRecordsToRead == maxRecords) { |
| return null; |
| } |
| return clone(this, maxRecords); |
| } |
| |
| public SystemTable getTable() { |
| return table; |
| } |
| |
| public int getMaxRecordsToRead() { |
| return maxRecordsToRead; |
| } |
| |
| @JsonIgnore |
| public SystemTablePlugin getPlugin() { |
| return plugin; |
| } |
| } |