[KYLIN-4831] sql error when max/min/sum param is constant

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Duplicate
• Affects Version/s: v3.1.0
• Fix Version/s: v3.1.4
• Component/s: Query Engine
• Assignee: Unassigned
• Reporter: hcy
• Created: 01/Dec/20 08:45
• Updated: 03/Nov/21 06:59
• Resolved: 03/Nov/21 06:59

Description

如果聚合函数中是常量(字符串或数字)时，报cube未命中的错误。

通过在DefaultQueryTransformer中正则匹配转换可以解决部分问题，如max('aaa')=>'aaa',sum(10)=>10*count(1).

但是怎么样从后端解决呢？因为从前端通过正则替换的方式解决会面临一些问题，如SUM(cast(1.22 as bigint))) 会替换为1.22*count(1)，没有达到数据转换cast的效果，当然也可以匹配出bigint从前端做转换，但总觉得在后端做会更好更彻底。在某些查询场景下，这类SQL无法避免。

test cube "KYLINS_SALES_CUBE"

test sql:

select ops_region,
max('AAA'),
min('AAA'),
sum(10)
from kylin_sales
group by ops_region

error log:

No realization found for OLAPContext, CUBE_NOT_READY, CUBE_NOT_READY, CUBE_NOT_READY, CUBE_NOT_READY, CUBE_NOT_READY, CUBE_NOT_READY, CUBE_UNMATCHED_AGGREGATION[FunctionDesc [expression=MIN, parameter=UNKNOWN_MODEL:DEFAULT._KYLIN_TABLE.AAA, returnType=null], FunctionDesc [expression=MAX, parameter=UNKNOWN_MODEL:DEFAULT._KYLIN_TABLE.AAA, returnType=null]], CUBE_NOT_READY, CUBE_NOT_READY, CUBE_NOT_READY, CUBE_NOT_READY, CUBE_NOT_READY, CUBE_NOT_READY, CUBE_NOT_READY, CUBE_NOT_READY, CUBE_NOT_READY, CUBE_NOT_READY, CUBE_NOT_READY, rel#482:OLAPTableScan.OLAP.[](table=[DEFAULT, KYLIN_SALES],ctx=,fields=[0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12]) while executing SQL: "select ops_region, max('AAA'), min('AAA'), 10*count(1) from kylin_sales group by ops_region"

 

Issue Links

• is duplicated by: KYLIN-4832 No realization found error when max/min param is expression