最佳性能 SQL 查询 SSRS

Question

I'm building a report and I'm in a dilemma which path to follow to reach better performance.

I got a table where

COD | CTYPID | MNT

The above contains COD as the primary key, type and amount

The report will contain each type as a column. Meaning one COD will have 3 columns for each CTYPID .

Which one is the best:

1-

   Insert into #temp
   Select sum(amount),CTYPID From table
   Group by COD,CTYPIDz

Then I left join this table with my main table where CTYPID=1 Then another left join where CTYPID=2 and so one

2-

 --insert in a temp table on multiple columns
   insert into #temp
   (Select sum(amount) column1,CTYPID From table where CTYPID=1
   Group by COD)
   Left join (Select sum(amount)column2 ,CTYPID From table where CTYPID=2
   Group by COD)

Then join the above with my main table

Answer 1

One alternative option would be to do conditional aggregation:

insert into #temp
select
    cod,
    sum(case when ctypid = 1 then mnt else 0 end) mnt_ctypid1,
    sum(case when ctypid = 2 then mnt else 0 end) mnt_ctypid2,
    sum(case when ctypid = 3 then mnt else 0 end) mnt_ctypid3
from mytable 
group by cod

For this query, you want an index on (cod, ctypid) (which might be already there since this seems to - or should - be the primary key of your table).