Oracle自动增量功能:11.2中的触发器还是Oracle JDBC CallableStatement? [英] Oracle Autoincrement Functionality: Triggers or Oracle JDBC CallableStatement in 11.2?

问题描述

当需要使用JDBC检索新生成的密钥时，哪种方法(就插入性能而言)是在Oracle(11.2)中实现自动增量功能的最佳方法?

Which is the best way (in terms of insert performance) to implement autoincrement functionality in Oracle (11.2) when you need to retrieved the newly generated key using JDBC?

我知道Oracle 12中有标识列，但是我现在仍然坚持使用11.2.

I know there are identity columns in Oracle 12, but I'm stuck with 11.2 right now.

与其他许多人一样，我没有让JDBC getGeneratedKeys()与Oracle一起工作的运气.我最终在Oracle(11.2)数据库中获得了触发器，该触发器的行为类似于MySQL自动增量函数，并在该表中有插入内容时从表特定的序列中插入NextVal作为其主键.但是，这使获取新插入的密钥变得困难，我最终进行了第二次查询以获取新生成的密钥.

Like many others, I have had no luck in getting the JDBC getGeneratedKeys() to work with Oracle. I ended up having trigger in my Oracle (11.2) database that acts like a MySQL autoincrement function and inserts the NextVal from a table specific sequence to act as its primary key whenever there is an insert into that table. This made getting the newly inserted key difficult though, I ended up doing a 2nd query to get the newly generated key.

最近，我发现了带有返回值的CallableStatement，并且我发现如何通过1次调用将其用于所有操作.

More recently I discovered CallableStatement with return values and I see how these could be used to do everything with 1 call.

当您还需要新生成的密钥时，后一种方法通常是插入的一种更快的方法吗?或者我找不到更好的选择吗?

Is this last method generally a faster way of doing inserts when you also need that newly generated key or is there a better option for me that I am missing?

推荐答案

我在迷你基准测试中得到了有趣的结果，并决定共享它.

I've got interesing result in my mini-benchmark and decide to share it.

测试代码:

import org.springframework.jdbc.support.JdbcUtils;
import org.springframework.util.Assert;
import org.springframework.util.StopWatch;

import java.sql.*;

public class TriggerPerformanceTest {
    private static final int STEPS_COUNT = 1000;

    public static void main(String[] args) throws SQLException {
        final Connection connection = DriverManager.getConnection("jdbc:oracle:thin:@host:1521/oradev", "user", "pass");

        prepare(connection);

        final StopWatch stopWatch = new StopWatch("mini-bench");

        testTrigger(connection, stopWatch);
        testSequence(connection, stopWatch);
        testSeparateCalls(connection, stopWatch);

        JdbcUtils.closeConnection(connection);

        System.out.println(stopWatch.prettyPrint());
    }

    private static void testTrigger(Connection connection, StopWatch stopWatch) throws SQLException {
        final PreparedStatement preparedStatement = connection.prepareStatement("INSERT INTO test_table_trigger (text) VALUES (?)", new String[]{"ID"});
        stopWatch.start("with trigger");
        for (int i = 0; i < STEPS_COUNT; i++) {
            preparedStatement.setString(1, "test");
            preparedStatement.executeUpdate();

            final ResultSet resultSet = preparedStatement.getGeneratedKeys();
            final boolean next = resultSet.next();
            Assert.state(next, "Expected not empty result set with generated keys");
            final long id = resultSet.getLong(1);
            Assert.state(id > 0, "Expected generated key value");
            JdbcUtils.closeResultSet(resultSet);
        }
        stopWatch.stop();
        JdbcUtils.closeStatement(preparedStatement);
    }

    private static void testSequence(Connection connection, StopWatch stopWatch) throws SQLException {
        final PreparedStatement preparedStatement = connection.prepareStatement("INSERT INTO test_table_sequence (id, text) VALUES (sq_test2.NEXTVAL, ?)", new String[]{"ID"});
        stopWatch.start("without trigger");
        for (int i = 0; i < STEPS_COUNT; i++) {
            preparedStatement.setString(1, "test");
            preparedStatement.executeUpdate();

            final ResultSet resultSet = preparedStatement.getGeneratedKeys();
            final boolean next = resultSet.next();
            Assert.state(next, "Expected not empty result set with generated keys");
            final long id = resultSet.getLong(1);
            Assert.state(id > 0, "Expected generated key value");
            JdbcUtils.closeResultSet(resultSet);
        }
        stopWatch.stop();
        JdbcUtils.closeStatement(preparedStatement);
    }

    private static void testSeparateCalls(Connection connection, StopWatch stopWatch) throws SQLException {
        final PreparedStatement preparedStatementSeq = connection.prepareStatement("SELECT sq_test3.NEXTVAL FROM dual");
        final PreparedStatement preparedStatement = connection.prepareStatement("INSERT INTO test_table_generated (id, text) VALUES (?, ?)");

        stopWatch.start("separate calls");
        for (int i = 0; i < STEPS_COUNT; i++) {
            final ResultSet resultSet = preparedStatementSeq.executeQuery();
            resultSet.next();
            final long id = resultSet.getLong(1);
            JdbcUtils.closeResultSet(resultSet);
            preparedStatement.setLong(1, id);
            preparedStatement.setString(2, "test");
            preparedStatement.executeUpdate();
        }
        stopWatch.stop();
        JdbcUtils.closeStatement(preparedStatementSeq);
        JdbcUtils.closeStatement(preparedStatement);
    }

    private static void prepare(Connection connection) throws SQLException {
        Statement statement = connection.createStatement();
        try {
            statement.execute("DROP TABLE test_table_sequence");
            statement.execute("DROP TABLE test_table_trigger");
            statement.execute("DROP TABLE test_table_generated");
            statement.execute("DROP SEQUENCE sq_test1");
            statement.execute("DROP SEQUENCE sq_test2");
            statement.execute("DROP SEQUENCE sq_test3");
        } catch (SQLException sqle) {
            //ignore
        }

        try {
            statement.execute("CREATE TABLE test_table_sequence (id NUMBER, text VARCHAR2(10))");
            statement.execute("CREATE TABLE test_table_trigger (id NUMBER, text VARCHAR2(10))");
            statement.execute("CREATE TABLE test_table_generated (id NUMBER, text VARCHAR2(10))");
            statement.execute("CREATE SEQUENCE sq_test1 START WITH 1 INCREMENT BY 1 CACHE 20");
            statement.execute("CREATE SEQUENCE sq_test2 START WITH 1 INCREMENT BY 1 CACHE 20");
            statement.execute("CREATE SEQUENCE sq_test3 START WITH 1 INCREMENT BY 1 CACHE 20");
            statement.execute("CREATE OR REPLACE TRIGGER trg_increment BEFORE INSERT ON test_table_trigger FOR EACH ROW\n" +
                              "BEGIN\n" +
                              "  SELECT sq_test1.NEXTVAL INTO :new.id FROM dual;\n" +
                              "END;");
        } catch (SQLException sqle) {
            sqle.printStackTrace();
        }

        try {
            statement.execute("TRUNCATE TABLE test_table_sequence");
            statement.execute("TRUNCATE TABLE test_table_trigger");
            statement.execute("TRUNCATE TABLE test_table_generated");
        } catch (SQLException sqle) {
            sqle.printStackTrace();
        }
    }
}

输出:

StopWatch 'mini-bench': running time (millis) = 27430
-----------------------------------------
ms     %     Task name
-----------------------------------------
09214  034%  with trigger
08916  033%  without trigger
09300  034%  separate calls

结论:差异很小...要考虑在内.

The conclusion: the difference quite small... to take it into consideration.

PS.专用Oracle 11.2.0.4，LAN 1Gb/s，Java 1.7.0_65.

PS. Dedicated Oracle 11.2.0.4, LAN 1Gb/s, Java 1.7.0_65.

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