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From "Zhou, Qianhao" <>
Subject Re: Too high cardinality is not suitable for dictionary
Date Wed, 18 Mar 2015 11:37:08 GMT
Hi dong
    MYDATE looks like a date to me. And if you are using date like
Œyyyy-MM-dd¹, there won¹t be so high cardinality. So I assume you are
introducing hours even seconds in the date column.
    The question is what are you using ³MYDATE² for? Do you really need
the data to be so specific?
    As a workaround, you can split the date into several derived column,
like year month date, hour(hour can be aggregated into 4 groups, like 0-6
7-12 13-18 19-24)

Best Regard
Zhou QianHao

On 3/18/15, 7:11 PM, "dong wang" <> wrote:

>I rebuilt the source code with the fix for issue 630, then, I select 2
>segments to merge, and each segment contains just one day's data, however,
>the following error occurs,
>java.lang.IllegalArgumentException: Too high cardinality is not suitable
>for dictionary -- DEFAULT.TEST.MYDATE cardinality: 7304854
>is there any suggestion about it?

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