paul-rogers commented on a change in pull request #1892: DRILL-7437: Storage Plugin for Generic HTTP REST API URL: https://github.com/apache/drill/pull/1892#discussion_r390552671
########## File path: contrib/storage-http/src/main/java/org/apache/drill/exec/store/http/HttpGroupScan.java ########## @@ -0,0 +1,167 @@ +/* + * 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.http; + +import java.util.Arrays; +import java.util.List; +import java.util.Objects; + +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.common.expression.SchemaPath; + +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.ScanStats.GroupScanProperty; +import org.apache.drill.exec.physical.base.SubScan; +import org.apache.drill.exec.proto.CoordinationProtos.DrillbitEndpoint; +import org.apache.drill.shaded.guava.com.google.common.base.MoreObjects; +import org.apache.drill.shaded.guava.com.google.common.base.Preconditions; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +@JsonTypeName("http-scan") +public class HttpGroupScan extends AbstractGroupScan { + private static final Logger logger = LoggerFactory.getLogger(HttpGroupScan.class); + + private List<SchemaPath> columns; + private final HttpScanSpec httpScanSpec; + private final HttpStoragePluginConfig config; + + public HttpGroupScan ( + HttpStoragePluginConfig config, + HttpScanSpec scanSpec, + List<SchemaPath> columns + ) { + super("no-user"); + this.config = config; + this.httpScanSpec = scanSpec; + this.columns = columns == null || columns.size() == 0 ? ALL_COLUMNS : columns; + } + + public HttpGroupScan(HttpGroupScan that) { + super(that); + config = that.config(); + httpScanSpec = that.httpScanSpec(); + columns = that.getColumns(); + } + + @JsonCreator + public HttpGroupScan( + @JsonProperty("config") HttpStoragePluginConfig config, + @JsonProperty("columns") List<SchemaPath> columns, + @JsonProperty("httpScanSpec") HttpScanSpec httpScanSpec + ) { + super("no-user"); + this.config = config; + this.columns = columns; + this.httpScanSpec = httpScanSpec; + } + + @JsonProperty("config") + public HttpStoragePluginConfig config() { return config; } + + @JsonProperty("columns") + public List<SchemaPath> columns() { return columns; } + + @JsonProperty("httpScanSpec") + public HttpScanSpec httpScanSpec() { return httpScanSpec; } + + @Override + public void applyAssignments(List<DrillbitEndpoint> endpoints) { + logger.debug("HttpGroupScan applyAssignments"); + } + + @Override + @JsonIgnore + public int getMaxParallelizationWidth() { + return 1; + } + + @Override + public boolean canPushdownProjects(List<SchemaPath> columns) { + return true; + } + + @Override + public SubScan getSpecificScan(int minorFragmentId) { + logger.debug("HttpGroupScan getSpecificScan"); + return new HttpSubScan(config, httpScanSpec, columns); + } + + @Override + public GroupScan clone(List<SchemaPath> columns) { + logger.debug("HttpGroupScan clone {}", columns); + HttpGroupScan newScan = new HttpGroupScan(this); + newScan.columns = columns; + return newScan; + } + + @Override + public String getDigest() { + return toString(); + } + + @Override + public PhysicalOperator getNewWithChildren(List<PhysicalOperator> children) { + Preconditions.checkArgument(children.isEmpty()); + return new HttpGroupScan(this); + } + + @Override + public ScanStats getScanStats() { + int colCount = columns.size(); + int estRowCount = 1; + int estDataSize = estRowCount * 200 * colCount; Review comment: This, unfortunately, does the *opposite* of what you want. When Drill does project, data size is 0. When you do project, data size is non-zero. Calcite will choose the cheapest, hence it will let Drill do the project. What you want is, if the columns are provided, reduce the data size. If not, leave data size at some assumed value. For example: ``` int rowWidth = 200; if (columns != null) { rowWidth = 100; } ``` Now we have another issue. If no columns are provided, we assume all columns. This means we cannot actually tell if anything is projected, since a `SELECT *` is the default case. So, rather than follow the copy/paste of prior plugins, might be better to leave `columns` null until project push-down occurs, and handle the `null` case when creating the readers. Sorry this is so hard. We really should fix it. ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: us...@infra.apache.org With regards, Apache Git Services
