Hi, all.
given a dimension table:
dim_table{
id_column int,
name_column string
}
and a fact table:
fact_table{
id_column int,
measure int
}
usually we select with this sql:
select
dim.id_column,
max(dim.name_column),
sum(fact.measure)
from fact_table as fact
join dim_table as dim
on fact.id_column = dim.id_column
group by dim.id_column
we just want to get the name column.
one way is to add the name_column as a derived dimension. But it costs
memory and slow down query.
another way is make name_column as a measure with max as aggregation
function. But kylin do not support Max on string type column.
Is there any better way to solve this problem?
thanks!
--
陈昊/Jerry Chen
Tel: (+86)15013773175
Email: jerrychen <zhangjian...@gmail.com>1...@gmail.com
P.C. 518055
Add: 中国广东省深圳市西丽大学城清华园H楼205
Room 205, Building H, Tsinghua Campus, The University Town, Shenzhen,
P.R.China
清华大学计算机科学与技术系
Department of Computer Science and Technology, Tsinghua University
