org.apache.calcite.adapter.pig.PigTable Maven / Gradle / Ivy
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* 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.calcite.adapter.pig;
import org.apache.calcite.plan.RelOptCluster;
import org.apache.calcite.plan.RelOptTable;
import org.apache.calcite.plan.RelOptTable.ToRelContext;
import org.apache.calcite.rel.RelNode;
import org.apache.calcite.rel.type.RelDataType;
import org.apache.calcite.rel.type.RelDataTypeFactory;
import org.apache.calcite.schema.TranslatableTable;
import org.apache.calcite.schema.impl.AbstractTable;
import org.apache.pig.data.DataType;
/**
* Represents a Pig relation that is created by Pig Latin
*
* LOAD statement.
*
* Only the default load function is supported at this point (PigStorage()).
*
*
Only VARCHAR (CHARARRAY in Pig) type supported at this point.
*
* @see PigTableFactory
*/
public class PigTable extends AbstractTable implements TranslatableTable {
private final String filePath;
private final String[] fieldNames;
/** Creates a PigTable. */
public PigTable(String filePath, String[] fieldNames) {
this.filePath = filePath;
this.fieldNames = fieldNames;
}
@Override public RelDataType getRowType(RelDataTypeFactory typeFactory) {
final RelDataTypeFactory.Builder builder = typeFactory.builder();
for (String fieldName : fieldNames) {
// only supports CHARARRAY types for now
final RelDataType relDataType = typeFactory
.createSqlType(PigDataType.valueOf(DataType.CHARARRAY).getSqlType());
final RelDataType nullableRelDataType = typeFactory
.createTypeWithNullability(relDataType, true);
builder.add(fieldName, nullableRelDataType);
}
return builder.build();
}
public String getFilePath() {
return filePath;
}
@Override public RelNode toRel(ToRelContext context, RelOptTable relOptTable) {
final RelOptCluster cluster = context.getCluster();
return new PigTableScan(cluster, cluster.traitSetOf(PigRel.CONVENTION), relOptTable);
}
}