Kylin will encode the dimension values with Dictionary (default encoding)
or other encoding methods when composing the rowkey; so the overhead will
be less in most of cases.
2016-12-02 17:59 GMT+08:00 Alberto Ramón :
> yes, I will asume this overhead in rowKey
>
> 2016-12-02 9:58 GMT+01:00 Billy(
yes, I will asume this overhead in rowKey
2016-12-02 9:58 GMT+01:00 Billy(Yiming) Liu :
> Using Joint Dimension for your 1:1 relation is the right design.
>
> 2016-12-02 0:21 GMT+08:00 Alberto Ramón :
>
>> Nice Liu
>>
>> We have some cases like
>> DayWeekTXT , DayWeekID
>> MonthTXT, MonthID
>>
>>
Using Joint Dimension for your 1:1 relation is the right design.
2016-12-02 0:21 GMT+08:00 Alberto Ramón :
> Nice Liu
>
> We have some cases like
> DayWeekTXT , DayWeekID
> MonthTXT, MonthID
>
> small proposal:
> Can would be interesting create Derived with 1:1 relation, with support
> for filter
Nice Liu
We have some cases like
DayWeekTXT , DayWeekID
MonthTXT, MonthID
small proposal:
Can would be interesting create Derived with 1:1 relation, with support for
filters and Group by
2016-12-01 11:55 GMT+01:00 Billy(Yiming) Liu :
> The cost of joint dimension compared with extended column i
The cost of joint dimension compared with extended column is you have more
columns in the HBase rowkey. It may harm the query performance. But most
time, joint dimension is still recommended, since the normal dimension
column supports much more functions than extended column, such as count(*).
201
Hello
I was preparing a email with related doubts:
Some times we have derived dimensions with relation 1:1, examples:
WeekDayID & WeekDayTxt
MonthID & WeekTxt
SOL1: Derived. ID as Host and Txt Extended
PB: You can't filter / Group by Txt
SOL2: Joint. Define tuples of ID & TXT
Some PB/limitation
Thanks, Alberto. The explanation is accurate. EXTENDED_COLUMN is only used
for representation, but not filtering or grouping which is done by
HOST_COLUMN. So EXTENDED_COLUMN is not a dimension, it works like a
key/value map against the HOST_COLUMN.
If the value in EXTENDED_COLUMN is not long, you
Hi ,all
I don’t understand the usage scenarios of EXTENDED_COLUMN,although I saw this
article “https://issues.apache.org/jira/browse/KYLIN-1313”.
What,s the means about parameters of “Host Column” and “Extended Column”? Why
use this expression,and what aspects of optimization that this expressio
