You are viewing a plain text version of this content. The canonical link for it is here.
Posted to dev@carbondata.apache.org by Jatin Demla <ja...@knoldus.in> on 2018/03/21 15:47:23 UTC

Getting Different Encoding in timestamp and date datatype.

Hi,

while analyzing an issue related to filter query on timestamp(or Date)
column,
I found that, in case of Timestamp datatype, the encoding list is having
only INVERTED_INDEX encoding and in case of Date datatype the encoding list
contains DIRECT_DICTIONARY, DICTIONARY and INVERTED_INDEX.

Is it correct to have different encoding list for date and timestamp
datatype?
-- 
Thanks & Regards
Jatin

Re: Getting Different Encoding in timestamp and date datatype.

Posted by David CaiQiang <da...@gmail.com>.
The direct dictionary ignores the millisecond of the timestamp data.
If the millisecond is needless, the direct dictionary uses the integer to
improve compression.



-----
Best Regards
David Cai
--
Sent from: http://apache-carbondata-dev-mailing-list-archive.1130556.n5.nabble.com/

Re: Getting Different Encoding in timestamp and date datatype.

Posted by Jatin Demla <ja...@knoldus.in>.
Hi David

Thanks for the reply.
As per the earlier implementation, both date and timestamp data types were
treated as Direct Dictionary type and for both the keys were generated
using the DirectDictionaryKeyGenerator.
Now the behavior is changed and timestamp is treated as no dictionary by
default. I am not clear why this behavior is changed. Can you please
clarify my doubt?


On Thu, Mar 22, 2018 at 9:06 AM, David CaiQiang <da...@gmail.com>
wrote:

> Hi Jatin, Timestamp column is non-dictionary by default. After adding the
> Timestamp column to the table property 'dictionary_include', it will have
> the same encoding list.
>
>
>
>
>
> -----
> Best Regards
> David Cai
> --
> Sent from: http://apache-carbondata-dev-mailing-list-archive.1130556.
> n5.nabble.com/
>



-- 
Thanks & Regards
Jatin

Re: Getting Different Encoding in timestamp and date datatype.

Posted by David CaiQiang <da...@gmail.com>.
Hi Jatin, Timestamp column is non-dictionary by default. After adding the
Timestamp column to the table property 'dictionary_include', it will have
the same encoding list.





-----
Best Regards
David Cai
--
Sent from: http://apache-carbondata-dev-mailing-list-archive.1130556.n5.nabble.com/