Oracle性能调优

Question

我有下面的甲骨文查询。它需要很长时间才能运行。您能为这个查询提供一些性能调优建议吗？

select ss.registration_id as REGISTRATION_ID,
       ss.batch_id as BATCH_ID
  from submtd_srvc PARTITION(SUBMTD_SRVC_821370) ss,
       (select a.exceptn_criteria_val,
               a.exceptn_criteria_rtrn_val 
          from EXCEPTN_CRITERIA a,
               EXCEPTN_EXPRESSION b
          where a.EXCEPTN_EXPRESSION_ID = b.EXCEPTN_EXPRESSION_ID
            and b.EXCEPTN_EXPRESSION_NAME = 'NC_CUSTOM_REV_CAT'
            and b.IS_CURRENT_INDCTR = 1
            and a.IS_CURRENT_INDCTR = 1) sub_query
  where ss.REVENUE_CD = sub_query.exceptn_criteria_val
    and ss.batch_id =  821370
    and exists (select 'x'
                  from submtd_srvc PARTITION(SUBMTD_SRVC_821370) ss2,
                       (select a.exceptn_criteria_val,
                               a.exceptn_criteria_rtrn_val 
                          from EXCEPTN_CRITERIA a,
                               EXCEPTN_EXPRESSION b
                          where a.EXCEPTN_EXPRESSION_ID = b.EXCEPTN_EXPRESSION_ID
                            and b.EXCEPTN_EXPRESSION_NAME = 'NC_CUSTOM_REV_CAT'
                            and b.IS_CURRENT_INDCTR = 1
                            and a.IS_CURRENT_INDCTR = 1) sub_query2
                  where ss2.REVENUE_CD = sub_query2.exceptn_criteria_val
                    and ss2.registration_id = ss.registration_id
                    and ss2.batch_id = ss.batch_id
                    and ss2.batch_id = 821370
                    and sub_query2.exceptn_criteria_rtrn_val <> sub_query.exceptn_criteria_rtrn_val)
  Order By Ss.Registration_Id,
           ss.batch_id;

Answer 1

如果我理解正确的话，您可以使用相关子查询来查找具有多个不同exceptn_criteria_rtrn_val值的行。如果我是对的，最好使用解析函数：

select vw.registration_id as REGISTRATION_ID, vw.batch_id as BATCH_ID
from
 (select ss.registration_id as REGISTRATION_ID, ss.batch_id as BATCH_ID
        ,count(distinct sub_query.exceptn_criteria_rtrn_val) over(partition by ss.registration_id, ss.batch_id) as cnt
    from submtd_srvc PARTITION(SUBMTD_SRVC_821370) ss,
         (select a.exceptn_criteria_val, a.exceptn_criteria_rtrn_val
            from EXCEPTN_CRITERIA a, EXCEPTN_EXPRESSION b
           where a.EXCEPTN_EXPRESSION_ID = b.EXCEPTN_EXPRESSION_ID
             and b.EXCEPTN_EXPRESSION_NAME = 'NC_CUSTOM_REV_CAT'
             and b.IS_CURRENT_INDCTR = 1
             and a.IS_CURRENT_INDCTR = 1) sub_query
   where ss.REVENUE_CD = sub_query.exceptn_criteria_val
     and ss.batch_id = 821370) vw
where cnt > 1
Order By vw.Registration_Id, vw.batch_id;

Answer 2

您可以将EXISTS替换为GROUP BY和HAVING

SELECT ss.registration_id,
       ss.batch_id
FROM   submtd_srvc PARTITION(SUBMTD_SRVC_821370) ss
       INNER JOIN
       EXCEPTN_CRITERIA a
       ON ( ss.REVENUE_CD = a.exceptn_criteria_val )
       INNER JOIN
       EXCEPTN_EXPRESSION b
       ON ( a.EXCEPTN_EXPRESSION_ID = b.EXCEPTN_EXPRESSION_ID )
WHERE  b.EXCEPTN_EXPRESSION_NAME = 'NC_CUSTOM_REV_CAT'
AND    b.IS_CURRENT_INDCTR = 1
AND    a.IS_CURRENT_INDCTR = 1
AND    ss.batch_id =  821370
GROUP BY
       ss.Registration_Id,
       ss.batch_id
HAVING COUNT( DISTINCT a.exceptn_criteria_rtrn_val ) = 1
ORDER BY
       ss.Registration_Id,
       ss.batch_id;

我还去掉了所有子查询，使用了ANSI标准连接，而不是遗留的Oracle连接。