优化有标量子查询的SQL

数据库环境：SQL SERVER 2008R2

今天在数据库中抓出一条比较耗费资源的SQL，只返回904条数据，居然跑了40多分钟。SQL及对应的数据量如下图：

SELECT  saft04.cur_year ,
        LEFT(saft04.dept_id, 4) sdept_id ,
        saft04.vdept_id ,
        saft04.dept_id ,
        saft04.fee_id ,
        saft04.vitem_id ,
        ISNULL(saft04.fee_amt, 0) AS saft04_fee_amt ,
        ISNULL(saft04.fee_qty, 0) AS saft04_fee_qty ,
        ISNULL(saft04.fee_amt_flex, 0) AS saft04_fee_amt_flex ,
        ISNULL(saft04.adj_amt, 0) AS saft04_adj_amt ,
        ISNULL(saft04.init_amt, 0) AS saft04_init_amt ,
        ISNULL(saft04.flex_amt, 0) AS saft04_flex_amt ,
        ISNULL(saft04.conf_fee_amt, 0) AS saft04_conf_fee_amt ,
        saft04.fc_app_no ,
        saft04.zone_id ,
        saft04.corr_id ,
        CASE WHEN saft04.fc_app_no < '2010'
             THEN ( CASE WHEN saft04.flexfapp_flag = 'Y'
                         THEN ISNULL(fee_amt, 0) + ISNULL(adj_amt, 0)
                              - ISNULL(conf_fee_amt, 0)
                         ELSE ISNULL(init_amt, 0) + ISNULL(flex_amt, 0)
                              + ISNULL(adj_amt, 0) - ISNULL(conf_fee_amt, 0)
                    END )
             ELSE CASE WHEN b.fee_type2 = '01'
                            OR b.fee_type2 = '02'
                       THEN ISNULL(fee_amt, 0) + ISNULL(adj_amt, 0)
                            - ISNULL(conf_fee_amt, 0)
                       WHEN b.fee_type2 = '03'
                       THEN ISNULL(init_amt, 0) + ISNULL(flex_amt, 0)
                            + ISNULL(adj_amt, 0) - ISNULL(conf_fee_amt, 0)
                  END
        END bal_amt ,
        ISNULL(( SELECT SUM(b.opr_amt)
                 FROM   v_saft04_fexp b
                 WHERE  b.fcapp_id = saft04.fc_app_no
               ), 0) AS qty1 ,
        CASE WHEN b.fee_type2 = '01'
                  OR b.fee_type2 = '03'
             THEN ISNULL(saft04.conf_fee_amt, 0)
                  - ( ISNULL(( SELECT   SUM(b.opr_amt)
                               FROM     v_saft04_fexp b
                               WHERE    b.fcapp_id = saft04.fc_app_no
                             ), 0) )
             WHEN b.fee_type2 = '02'
             THEN ISNULL(saft04.init_amt, 0) + ISNULL(saft04.flex_amt, 0)
                  - ISNULL(( SELECT SUM(b.opr_amt)
                             FROM   v_saft04_fexp b
                             WHERE  b.fcapp_id = saft04.fc_app_no
                           ), 0)
                  + ISNULL(( SELECT SUM(d.opr_amt)
                             FROM   v_fadj_rd d
                             WHERE  d.fcapp_id = saft04.fc_app_no
                           ), 0)
        END qty2 ,
        c.base_data2
FROM    saft04
        LEFT JOIN v_ctlm60 b ON b.fee_id = saft04.fee_id
        LEFT JOIN ctlm1000 c ON c.d_type = 'fee_type2'
                                AND b.fee_type2 = c.base_data1
WHERE   1 = 1
        AND saft04.com_id = 'LQPJ'
        AND saft04.cur_year = 2015
        AND saft04.dept_id LIKE '2001%'
        AND ( saft04.dept_id IN ( SELECT    dept_id
                                  FROM      ctlm2000
                                  WHERE     user_id1 = '0100030' )
              OR '0100030' = 'MANAGER'
            )
ORDER BY saft04.cur_year ,
        saft04.vdept_id ,
        saft04.dept_id ,
        saft04.fee_id ,
        saft04.vitem_id ,
        saft04.zone_id ,
        saft04.corr_id ,
        saft04.fc_app_no
-------------------------数据量统计----------------------------------
SELECT  COUNT(*)
FROM    saft04
WHERE   1 = 1
        AND saft04.com_id = 'LQPJ'
        AND saft04.cur_year = 2015
        AND saft04.dept_id LIKE '%2001%'
        AND ( saft04.dept_id IN ( SELECT    dept_id
                                  FROM      ctlm2000
                                  WHERE     user_id1 = '0100030' )
              OR '0100030' = 'MANAGER'
            )--904
SELECT COUNT(*) FROM  v_saft04_fexp  --1262584
SELECT COUNT(*) FROM  v_fadj_rd d --37077
SELECT COUNT(*) FROM  v_ctlm60 --431
SELECT COUNT(*) FROM  ctlm1000 --377

看了一下SQL，有可能出现问题的地方有2个地方，第一个是saft04 表的过滤条件“saft04.dept_id LIKE '%2001%'”使用了模糊查询，导致

走不了既定的索引。经和业务员确定，最开始只是想查询以“2001”开头的单位，因此，这个条件改成“saft04.dept_id LIKE '2001%'”即可。

第二个问题，是最要命的，标量部分“SELECT SUM(b.opr_amt) FROM v_saft04_fexp b WHERE b.fcapp_id = saft04.fc_app_no”走

的执行计划是嵌套循环，因而要改成左联接。

改写后的SQL如下，只执行了23S就全部出结果了。

WITH    x0
          AS ( SELECT   b.fcapp_id ,
                        SUM(b.opr_amt) opr_amt
               FROM     v_saft04_fexp b
               GROUP BY b.fcapp_id
             )
    SELECT  saft04.cur_year ,
            LEFT(saft04.dept_id, 4) sdept_id ,
            saft04.vdept_id ,
            saft04.dept_id ,
            saft04.fee_id ,
            saft04.vitem_id ,
            ISNULL(saft04.fee_amt, 0) AS saft04_fee_amt ,
            ISNULL(saft04.fee_qty, 0) AS saft04_fee_qty ,
            ISNULL(saft04.fee_amt_flex, 0) AS saft04_fee_amt_flex ,
            ISNULL(saft04.adj_amt, 0) AS saft04_adj_amt ,
            ISNULL(saft04.init_amt, 0) AS saft04_init_amt ,
            ISNULL(saft04.flex_amt, 0) AS saft04_flex_amt ,
            ISNULL(saft04.conf_fee_amt, 0) AS saft04_conf_fee_amt ,
            saft04.fc_app_no ,
            saft04.zone_id ,
            saft04.corr_id ,
            CASE WHEN saft04.fc_app_no < '2010'
                 THEN ( CASE WHEN saft04.flexfapp_flag = 'Y'
                             THEN ISNULL(fee_amt, 0) + ISNULL(adj_amt, 0)
                                  - ISNULL(conf_fee_amt, 0)
                             ELSE ISNULL(init_amt, 0) + ISNULL(flex_amt, 0)
                                  + ISNULL(adj_amt, 0) - ISNULL(conf_fee_amt,
                                                              0)
                        END )
                 ELSE CASE WHEN b.fee_type2 = '01'
                                OR b.fee_type2 = '02'
                           THEN ISNULL(fee_amt, 0) + ISNULL(adj_amt, 0)
                                - ISNULL(conf_fee_amt, 0)
                           WHEN b.fee_type2 = '03'
                           THEN ISNULL(init_amt, 0) + ISNULL(flex_amt, 0)
                                + ISNULL(adj_amt, 0) - ISNULL(conf_fee_amt, 0)
                      END
            END bal_amt ,
            ISNULL(( x0.opr_amt ), 0) AS qty1 ,
            CASE WHEN b.fee_type2 = '01'
                      OR b.fee_type2 = '03'
                 THEN ISNULL(saft04.conf_fee_amt, 0) - ( ISNULL(( x0.opr_amt ),
                                                              0) )
                 WHEN b.fee_type2 = '02'
                 THEN ISNULL(saft04.init_amt, 0) + ISNULL(saft04.flex_amt, 0)
                      - ISNULL(( x0.opr_amt ), 0)
                      + ISNULL(( SELECT SUM(d.opr_amt)
                                 FROM   v_fadj_rd d
                                 WHERE  d.fcapp_id = saft04.fc_app_no
                               ), 0)
            END qty2 ,
            c.base_data2
    FROM    saft04
            LEFT JOIN v_ctlm60 b ON b.fee_id = saft04.fee_id
            LEFT JOIN ctlm1000 c ON c.d_type = 'fee_type2'
                                    AND b.fee_type2 = c.base_data1
            LEFT JOIN x0 ON x0.fcapp_id = saft04.fc_app_no
    WHERE   1 = 1
            AND saft04.com_id = 'LQPJ'
            AND saft04.cur_year = 2015
            AND saft04.dept_id LIKE '2001%'
            AND saft04.dept_id IN ( SELECT  dept_id
                                    FROM    ctlm2000
                                    WHERE   user_id1 = '0100030' )
    ORDER BY saft04.cur_year ,
            saft04.vdept_id ,
            saft04.dept_id ,
            saft04.fee_id ,
            saft04.vitem_id ,
            saft04.zone_id ,
            saft04.corr_id ,
            saft04.fc_app_no

改写后的SQL还有一个标量子查询没处理，改写的思路和上面一样，因执行时间已经缩短到23S，就不改了。