JDBC批量Insert深度优化（有事务）

环境：

MySQL 5.1

RedHat Linux AS 5

JavaSE 1.5

DbConnectionBroker 微型数据库连接池

 

测试的方案：

执行10万次Insert语句，使用不同方式。

 

A组：静态SQL，自动提交，没事务控制（MyISAM引擎）

1、逐条执行10万次

2、分批执行将10万分成m批，每批n条，分多种分批方案来执行。

 

B组：预编译模式SQL，自动提交，没事务控制（MyISAM引擎）

1、逐条执行10万次

2、分批执行将10万分成m批，每批n条，分多种分批方案来执行。

-------------------------------------------------------------------------------------------

C组：静态SQL，不自动提交，有事务控制（InnoDB引擎）

1、逐条执行10万次

2、分批执行将10万分成m批，每批n条，分多种分批方案来执行。

 

D组：预编译模式SQL，不自动提交，有事务控制（InnoDB引擎）

1、逐条执行10万次

2、分批执行将10万分成m批，每批n条，分多种分批方案来执行。

 

本次主要测试C、D组，并得出测试结果。

 

SQL代码

DROP TABLE IF EXISTS tuser;
CREATE TABLE tuser (     id bigint(20) NOT NULL AUTO_INCREMENT,     name varchar(12) DEFAULT NULL,     remark varchar(24) DEFAULT NULL,     createtime datetime DEFAULT NULL,     updatetime datetime DEFAULT NULL,     PRIMARY KEY (id) ) ENGINE=InnoDB AUTO_INCREMENT=1 DEFAULT CHARSET=utf8;

 

package testbatch;

import java.io.IOException;
import java.sql.*;

/**
* JDBC批量Insert优化（下）
*
* @author leizhimin 2009-7-29 10:03:10
*/
public class TestBatch {
        public static DbConnectionBroker myBroker = null;

        static {
                try {
                        myBroker = new DbConnectionBroker("com.mysql.jdbc.Driver",
                                        "jdbc:mysql://192.168.104.163:3306/testdb",
                                        "vcom", "vcom", 2, 4,
                                        "c:\testdb.log", 0.01);
                } catch (IOException e) {
                        e.printStackTrace();
                }
        }

        /**
         * 初始化测试环境
         *
         * @throws SQLException 异常时抛出
         */
        public static void init() throws SQLException {
                Connection conn = myBroker.getConnection();
                conn.setAutoCommit(false);
                Statement stmt = conn.createStatement();
                stmt.addBatch("DROP TABLE IF EXISTS tuser");
                stmt.addBatch("CREATE TABLE tuser ( " +
                                "    id bigint(20) NOT NULL AUTO_INCREMENT, " +
                                "    name varchar(12) DEFAULT NULL, " +
                                "    remark varchar(24) DEFAULT NULL, " +
                                "    createtime datetime DEFAULT NULL, " +
                                "    updatetime datetime DEFAULT NULL, " +
                                "    PRIMARY KEY (id) " +
                                ") ENGINE=InnoDB AUTO_INCREMENT=1 DEFAULT CHARSET=utf8");
                stmt.executeBatch();
                conn.commit();
                myBroker.freeConnection(conn);
        }

        /**
         * 100000条静态SQL插入
         *
         * @throws Exception 异常时抛出
         */
        public static void testInsert() throws Exception {
                init();         //初始化环境
                Long start = System.currentTimeMillis();
                for (int i = 0; i < 100000; i++) {
                        String sql = " " +
                                        "insert into testdb.tuser " +
                                        " (name, " +
                                        " remark, " +
                                        " createtime, " +
                                        " updatetime " +
                                        " ) " +
                                        " values " +
                                        " ('" + RandomToolkit.generateString(12) + "', " +
                                        " '" + RandomToolkit.generateString(24) + "', " +
                                        " now(), " +
                                        " now() " +
                                        ")";
                        Connection conn = myBroker.getConnection();
                        conn.setAutoCommit(false);
                        Statement stmt = conn.createStatement();
                        stmt.execute(sql);
                        conn.commit();
                        myBroker.freeConnection(conn);
                }
                Long end = System.currentTimeMillis();
                System.out.println("单条执行100000条Insert操作，共耗时：" + (end - start) / 1000f + "秒！");
        }

        /**
         * 批处理执行静态SQL测试
         *
         * @param m 批次
         * @param n 每批数量
         * @throws Exception 异常时抛出
         */
        public static void testInsertBatch(int m, int n) throws Exception {
                init();             //初始化环境
                Long start = System.currentTimeMillis();
                for (int i = 0; i < m; i++) {
                        //从池中获取连接
                        Connection conn = myBroker.getConnection();
                        conn.setAutoCommit(false);
                        Statement stmt = conn.createStatement();
                        for (int k = 0; k < n; k++) {
                                String sql = " " +
                                                "insert into testdb.tuser " +
                                                " (name, " +
                                                " remark, " +
                                                " createtime, " +
                                                " updatetime " +
                                                " ) " +
                                                " values " +
                                                " ('" + RandomToolkit.generateString(12) + "', " +
                                                " '" + RandomToolkit.generateString(24) + "', " +
                                                " now(), " +
                                                " now() " +
                                                ")";
                                //加入批处理
                                stmt.addBatch(sql);
                        }
                        stmt.executeBatch();    //执行批处理
                        conn.commit();
//                        stmt.clearBatch();        //清理批处理
                        stmt.close();
                        myBroker.freeConnection(conn); //连接归池
                }
                Long end = System.currentTimeMillis();
                System.out.println("批量执行" + m + "*" + n + "=" + m * n + "条Insert操作，共耗时：" + (end - start) / 1000f + "秒！");
        }

        /**
         * 100000条预定义SQL插入
         *
         * @throws Exception 异常时抛出
         */
        public static void testInsert2() throws Exception {     //单条执行100000条Insert操作，共耗时：40.422秒！
                init();         //初始化环境
                Long start = System.currentTimeMillis();
                String sql = "" +
                                "insert into testdb.tuser " +
                                "    (name, remark, createtime, updatetime) " +
                                "values " +
                                "    (?, ?, ?, ?)";
                for (int i = 0; i < 100000; i++) {
                        Connection conn = myBroker.getConnection();
                        conn.setAutoCommit(false);
                        PreparedStatement pstmt = conn.prepareStatement(sql);
                        pstmt.setString(1, RandomToolkit.generateString(12));
                        pstmt.setString(2, RandomToolkit.generateString(24));
                        pstmt.setDate(3, new Date(System.currentTimeMillis()));
                        pstmt.setDate(4, new Date(System.currentTimeMillis()));
                        pstmt.executeUpdate();
                        conn.commit();
                        pstmt.close();
                        myBroker.freeConnection(conn);
                }
                Long end = System.currentTimeMillis();
                System.out.println("单条执行100000条Insert操作，共耗时：" + (end - start) / 1000f + "秒！");
        }

        /**
         * 批处理执行预处理SQL测试
         *
         * @param m 批次
         * @param n 每批数量
         * @throws Exception 异常时抛出
         */
        public static void testInsertBatch2(int m, int n) throws Exception {
                init();             //初始化环境
                Long start = System.currentTimeMillis();
                String sql = "" +
                                "insert into testdb.tuser " +
                                "    (name, remark, createtime, updatetime) " +
                                "values " +
                                "    (?, ?, ?, ?)";
                for (int i = 0; i < m; i++) {
                        //从池中获取连接
                        Connection conn = myBroker.getConnection();
                        conn.setAutoCommit(false);
                        PreparedStatement pstmt = conn.prepareStatement(sql);
                        for (int k = 0; k < n; k++) {
                                pstmt.setString(1, RandomToolkit.generateString(12));
                                pstmt.setString(2, RandomToolkit.generateString(24));
                                pstmt.setDate(3, new Date(System.currentTimeMillis()));
                                pstmt.setDate(4, new Date(System.currentTimeMillis()));
                                //加入批处理
                                pstmt.addBatch();
                        }
                        pstmt.executeBatch();    //执行批处理
                        conn.commit();
//                        pstmt.clearBatch();        //清理批处理
                        pstmt.close();
                        myBroker.freeConnection(conn); //连接归池
                }
                Long end = System.currentTimeMillis();
                System.out.println("批量执行" + m + "*" + n + "=" + m * n + "条Insert操作，共耗时：" + (end - start) / 1000f + "秒！");
        }

        public static void main(String[] args) throws Exception {
                init();
                Long start = System.currentTimeMillis();
                System.out.println("--------C组测试----------");
                testInsert();
                testInsertBatch(100, 1000);
                testInsertBatch(250, 400);
                testInsertBatch(400, 250);
                testInsertBatch(500, 200);
                testInsertBatch(1000, 100);
                testInsertBatch(2000, 50);
                testInsertBatch(2500, 40);
                testInsertBatch(5000, 20);
                Long end1 = System.currentTimeMillis();
                System.out.println("C组测试过程结束，全部测试耗时：" + (end1 - start) / 1000f + "秒！");

                System.out.println("--------D组测试----------");
                testInsert2();
                testInsertBatch2(100, 1000);
                testInsertBatch2(250, 400);
                testInsertBatch2(400, 250);
                testInsertBatch2(500, 200);
                testInsertBatch2(1000, 100);
                testInsertBatch2(2000, 50);
                testInsertBatch2(2500, 40);
                testInsertBatch2(5000, 20);

                Long end2 = System.currentTimeMillis();
                System.out.println("D组测试过程结束，全部测试耗时：" + (end2 - end1) / 1000f + "秒！");
        }
}

 

 

测试结果意想不到吧，最短时间竟然超过上篇。观察整个测试结果，发现总时间很长，原因是逐条执行的效率太低了。

 

结论：

 

在本测试条件下，得出结论：

 

数据库连接池控制下，不自动提交，事务控制（InnoDB引擎）

 

1、逐条执行的效率很低很低，尽可能避免逐条执行。

2、事务控制下，静态SQL的效率超过预处理SQL。

3、分批的大小对效率影响挺大的，一般来说，事务控制下，分批大小在100-1000之间比较合适。

4、谈到优化方式，上面的批处理就是很好的优化策略。

 

 

大总结：

 

对比上篇没事务的测试结果，得出一个全面的结论：

 

1、连接池最基本的也是最重要的优化策略，总能大幅提高性能。

 

2、批处理在效率上总是比逐条处理有优势，要处理的数据的记录条数越大，批处理的优势越明显，批处理还有一个好处就是减少了对数据库的链接次数，从而减轻数据库的压力。

 

3、批处理执行SQL的时候，批处理的分批的大小与数据库的吞吐量以及硬件配置有很大关系，需要通过测试找到最佳的分批大小，一般在50-1000之间。

 

4、预处理SQL在没事务的表上效率较高，在有实物的情况下比静态SQL稍有不及。但预定义SQL还有个好处就是消耗的内存较少，静态SQL串会占用大量的内存资源，容易导致内存溢出的问题。因此批量执行时候可以优先选择预定义SQL。

 

5、在批处理执行的时候，每批执行完成后，最好显式的调用pstmt.close()或stmt.close()方法，以便尽快释放执行过的SQL语句，提高内存利用率。

 

6、对于有大量SELECT操作，MyISAM是更好的选择；对于有大量INSERT和UPDATE操作的表，InnoDB效率更好。

 

7、虽然测试结果只能反映特定情况下的一些事实，以上的优化策略是普遍策略，可以明显缩短寻找最优策略的时间，对于效率要求很高的程序，还应该做并发性等测试。

 

8、测试是件很辛苦的事情，你需要有大量的事实来证明你的优化是有效的，而不能单单凭经验，因为每个机器的环境都不一样，使用的方式也不同。