Hello All,
After we build a cube successfully, then we use various sql
statements to query it. In my mind , the sql statement will converted to
hbase query command.
There are some problem I can't find the answer,please help me to
understand kylin and its principle more accurately.
1. If build a cloned cube succefully, it will get a new htable, then which
one is the exactly htable when using the same query statements ? in the
query page, i can see which cube it is, but then I have build the original
one again later, at this moment, my query use the cloned cube not the
original cube , why it doesn't use the original ?
2. I can't query the fact table using 'select * from fact_table', the error
message is 'Error while executing SQL "select * from tb_fact_new LIMIT
50000": When query with topN, only SUM function is allowed.'
3. What select statement can I use is valid in the query page or use kylin
api, in the other email titled ' SQL statements supported by kylinl
1.5',hongbin ma has answered that is the subset of sql which calcite
supported. .I find the select sql calcite supported is as follow:
select:
SELECT [ STREAM ] [ ALL | DISTINCT ]
{ * | projectItem [, projectItem ]* }
FROM tableExpression
[ WHERE booleanExpression ]
[ GROUP BY { groupItem [, groupItem ]* } ]
[ HAVING booleanExpression ]
[ WINDOW windowName AS windowSpec [, windowName AS windowSpec ]* ]
is that other select grammer is not supported except those ?
Thanks.
