SQL優化（group by和max）

Question

存在一個加速下面的sql查詢的機會？

select 
    max(xtrid) as xtrid 
    , jid 
from jpltab jl 
    inner join rb_cust u 
    on jl.custid = u.custid 
where jl.tpe = 'Y' 
    and jl.jid in (51, 52, 53, 54, 55) 
    and u.org = 'INVCE' 
group by jid 
order by xtrid desc; 

感謝

Answer 1

你可以拿出 'order by xtrid desc' 因爲你已經選擇了最大

Answer 2

這是您的查詢：

select jl.jid, max(xtrid) as xtrid 
from jpltab jl inner join 
    rb_cust u 
    on jl.custid = u.custid 
where jl.tpe = 'Y' and 
     jl.jid in (51, 52, 53, 54, 55) and 
     u.org = 'INVCE' 
group by jl.jid 
order by xtrid desc; 

我將開始與索引。想到的是jpltab(tpe, jid, custid)和rb_cust(custid, org)。