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表包含50万行,下面是我正在运行的选择查询,但这需要花费很长时间。此查询是否可以调整?使用UNION使用包含多个SUM()
聚合一个查询使用多个GROUP BY子句调整查询
select phone_number,rg,val from (
select phone_number, rg, sum(val) val from
(select /*+ PARALLEL(GPRS_CDR 3) */ phone_number, rg1 rg, sum(rg1_vol) val
from gprs_cdr
where day_of_year=to_char(sysdate -1,'ddd')
group by phone_number, rg1
union all
select /*+ PARALLEL(GPRS_CDR 3) */ phone_number, rg2 rg, sum(rg2_vol) val
from gprs_cdr
where day_of_year=to_char(sysdate -1,'ddd')
group by phone_number, rg2
union all
select /*+ PARALLEL(GPRS_CDR 3) */ phone_number, rg3 rg, sum(rg3_vol) val
from gprs_cdr
where day_of_year=to_char(sysdate -1,'ddd')
group by phone_number, rg3
union all
select /*+ PARALLEL(GPRS_CDR 3) */ phone_number, rg4 rg, sum(rg4_vol) val
from gprs_cdr
where day_of_year=to_char(sysdate -1,'ddd')
group by phone_number, rg4
union all
select /*+ PARALLEL(GPRS_CDR 3) */ phone_number, rg5 rg, sum(rg5_vol) val
from gprs_cdr
where day_of_year=to_char(sysdate -1,'ddd')
group by phone_number, rg5)
where rg = '31'
group by phone_number,rg
order by val desc
)
where rownum <= 20;
理智胜出...感谢反讽堆栈 –
显示表结构和示例数据。需要检查'RG2_VOL','RG3_VOL'等包含其他记录的值。 –