Java namedParameterJdbcTemplate批量更新vs插入选择

我正在做一个实验，我想看看在PostgreSQL数据库中插入多条记录的方法能给我带来最好的速度性能。我使用的是“PostgreSQL 1800, 64，1.8 C++ + java + +Postgres JDBC驱动程序：94.077./P>> 本实验的表定义如下：

CREATE TABLE mytable (ea VARCHAR(256) NOT NULL, ehv CHAR(60) NOT NULL);

ALTER TABLE mytable ADD CONSTRAINT pk_mytable_ea PRIMARY KEY (ea);

第一种方法是执行

executeBatch

，其中我创建了参数映射列表。代码如下所示：

public void executeBatch(List<MyObject> myObjects) {
        final String sql = "INSERT INTO mytable(" +
                "    ea, ehv) " +
                "    VALUES (:ea, :ehv) ";

        MapSqlParameterSource[] params = new MapSqlParameterSource[myObjects.size()];
        for (int i = 0; i < myObjects.size(); i++) {
            params[i] = new MapSqlParameterSource()
                    .addValue("ea", myObjects.get(i).getEa())
                    .addValue("ehv", myObjects.get(i).getEhv());
        }

        jdbcTemplate.batchUpdate(sql, params);
    }

我在下面的测试中比较了这两种方法，我创建了10000个MyObject

@Test
    public void test() throws JsonProcessingException, RepositoryException {
        List<MyObject> myObjects = new ArrayList(10000);
        for(int i = 0; i < 10000; i++) {
            myObjects.add(new MyObject(i + "ea", i + "ehv"));
        }

        long before = System.currentTimeMillis();
        censusRepository.executeBatch(myObjects);
        long after = System.currentTimeMillis();
        System.out.println("executeBatch Took - " + (after-before));

        namedParameterJdbcTemplate.update("delete from mytable", new MapSqlParameterSource());

        before = System.currentTimeMillis();
        censusRepository.insertFromString(myObjects);
        after = System.currentTimeMillis();
        System.out.println("insertFromString Took - " + (after-before));

        namedParameterJdbcTemplate.update("delete from mytable", new MapSqlParameterSource());
    }

是什么原因导致第二种方法的性能比

executeBatch

好得多？根据你的经验，我应该采取哪种方法。你能推荐另一个能给我更好表现的吗？我有以下限制-我将向数据库中插入1000个MyObject的批次，每个MyObject包含两个字符串值。

插入到。。。选择

插入到。。。值（…），（…）…插入到。。。值（…）。几乎总是这样。执行多个语句会增加每个语句的通信、准备等成本。将多个参数绑定到单个语句。请参见f.ex。

@Test
    public void test() throws JsonProcessingException, RepositoryException {
        List<MyObject> myObjects = new ArrayList(10000);
        for(int i = 0; i < 10000; i++) {
            myObjects.add(new MyObject(i + "ea", i + "ehv"));
        }

        long before = System.currentTimeMillis();
        censusRepository.executeBatch(myObjects);
        long after = System.currentTimeMillis();
        System.out.println("executeBatch Took - " + (after-before));

        namedParameterJdbcTemplate.update("delete from mytable", new MapSqlParameterSource());

        before = System.currentTimeMillis();
        censusRepository.insertFromString(myObjects);
        after = System.currentTimeMillis();
        System.out.println("insertFromString Took - " + (after-before));

        namedParameterJdbcTemplate.update("delete from mytable", new MapSqlParameterSource());
    }

executeBatch Took - 464ms
insertFromString Took - 253ms