ibatis 2.0分页方式的改进

        ibatis 2.0采用的是游标的方式进行分页，这种分页我认为对数据库段的压力大，且SQL也不一定高效，特别是数据量大的时候进行翻页。所以在用ibatis 2.0的时候，建议使用SQL分页。下面来做一个实验：

SQL> create table test as select * from dba_objects;

SQL> insert into test  select * from dba_objects;

SQL> insert into test  select * from test;

SQL> create table test1 as select * from dba_objects;

SQL> commit;
SQL> exec dbms_stats.gather_table_stats(user,'test');
SQL> select count(*) from test;
  COUNT(*)
----------

    202620

 下面的java测试代码中游标的分页是ibatis2.0的分页方式。

    

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.Statement;

public class Test {
    static final String driver_class  = "oracle.jdbc.driver.OracleDriver";
    static final String connectionURL = "jdbc:oracle:thin:@10.10.29.150:1522:ordb10";
    static final String userID        = "test";
    static final String userPassword  = "test";

    public static void main(String[] args) throws Exception{
        Test test = new Test();
        //test.queryContent();
        test.queryContent1();
    }

    public void queryContent() throws Exception {
        long startTime =System.currentTimeMillis();
        Connection  conn = null;
        PreparedStatement   pstmt = null;
        ResultSet   rset = null;
        String  strSQL = "SELECT * FROM (SELECT INNER_TABLE.*, ROWNUM OUTER_TABLE_ROWNUM "+
                " FROM (select t1.* from test t,test1 t1 where t1.object_id=t.object_id order by t1.object_name desc) INNER_TABLE "+
               " WHERE ROWNUM <= 200100) OUTER_TABLE "+
               " WHERE OUTER_TABLE_ROWNUM > 200000 ";
        try {
            Class.forName (driver_class).newInstance();
            conn = DriverManager.getConnection(connectionURL, userID, userPassword);
            pstmt = conn.prepareStatement(strSQL);
            rset = pstmt.executeQuery ();
            while (rset.next ()) {
                String s1 =rset.getString(1);
                String s2 =rset.getString(2);
                String s3 =rset.getString(3);
                String s4 =rset.getString(4);
                String s5 =rset.getString(5);
                String s6 =rset.getString(6);
            }
            long endTime =System.currentTimeMillis();
            System.out.println("rownum分页为:"+(endTime-startTime)+"ms");
        }catch (Exception e) {
            e.printStackTrace();
        }finally{
            if(rset != null) {
                rset.close();
            }
            if(pstmt != null) {
                pstmt.close();
            }
        }
    }

    public void queryContent1() throws Exception {
        long startTime =System.currentTimeMillis();
        Connection  conn = null;
        Statement    stmt = null;
        ResultSet   rs = null;
        String  strSQL = "select t1.* from test t,test1 t1 where t1.object_id=t.object_id order by t1.object_name desc";
        try {
            Class.forName (driver_class).newInstance();
            conn = DriverManager.getConnection(connectionURL, userID, userPassword);
            stmt = conn.createStatement(ResultSet.TYPE_FORWARD_ONLY, ResultSet.CONCUR_READ_ONLY);
            rs = stmt.executeQuery(strSQL);
            int j=0;
            //游标移动到N条数据的位置
            while(rs.next() && j++<200000){
            }
            int i=0;
            //依次取出36条数据
            while(rs.next() && i++<100){
                String s1 =rs.getString(1);
                String s2 =rs.getString(