Re: does anyone tell me why raw measure need dictionary?

[ShaoFeng Shi <sh...@apache.org>]

Awesome！

Best regards,

Shaofeng Shi 史少锋
Apache Kylin PMC
Email: shaofengshi@apache.org

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you Zhuang <zh...@gmail.com> 于2019年7月31日周三 下午9:19写道：

> Thanks ShaoFeng, I have copy a rawv2 measure without dictionary instead,
> all memory metrics have been around normal level since then.
>
> On Jul 31, 2019, at 1:16 PM, ShaoFeng Shi <sh...@apache.org> wrote:
>
> This is a limitation of the raw measure; It uses a dictionary to compress
> the values, but that may make the dictionary very big. This is one of the
> reasons that Kylin mark the raw measure as deprecated.
>
> Best regards,
>
> Shaofeng Shi 史少锋
> Apache Kylin PMC
> Email: shaofengshi@apache.org
>
> Apache Kylin FAQ: https://kylin.apache.org/docs/gettingstarted/faq.html
> Join Kylin user mail group: user-subscribe@kylin.apache.org
> Join Kylin dev mail group: dev-subscribe@kylin.apache.org
>
>
>
>
> you Zhuang <zh...@gmail.com> 于2019年7月15日周一 下午11:27写道：
>
>> I use raw measure to serve original records consults. But why does raw
>> measure need dictionary?  If I have a lot of raw measures, performance is
>> slow. I see code below :
>>
>> @Override
>> public List<TblColRef> getColumnsNeedDictionary(FunctionDesc functionDesc) {
>>     TblColRef literalCol = functionDesc.getParameter().getColRefs().get(0);
>>     return Collections.singletonList(literalCol);
>> }
>>
>>
>> My raw measures are always double, not big. So I don’t need dictionary at
>> all.
>>
>> I use raw measures for historical reasons, so I expect someone to tell me
>> why and how I can modify to use raw bytes.
>>
>
>