org.apache.beam.sdk.io.jdbc.JdbcReadWithPartitionsHelper Maven / Gradle / Ivy
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* Licensed to the Apache Software Foundation (ASF) under one
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* distributed with this work for additional information
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* 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,
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*/
package org.apache.beam.sdk.io.jdbc;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import org.apache.beam.sdk.io.jdbc.JdbcIO.PreparedStatementSetter;
import org.apache.beam.sdk.io.jdbc.JdbcIO.RowMapper;
import org.apache.beam.sdk.values.KV;
/**
* A helper for {@link JdbcIO.ReadWithPartitions} that handles range calculations.
*
* @param Element type of the column used for partition.
*/
public interface JdbcReadWithPartitionsHelper
extends PreparedStatementSetter>,
RowMapper>> {
/**
* Calculate the range of each partition from the lower and upper bound, and number of partitions.
*
* Return a list of pairs for each lower and upper bound within each partition.
*/
Iterable> calculateRanges(
PartitionT lowerBound, PartitionT upperBound, Long partitions);
@Override
void setParameters(KV element, PreparedStatement preparedStatement);
@Override
KV> mapRow(ResultSet resultSet) throws Exception;
}