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From Devopam Mittra <devo...@gmail.com>
Subject Re: VARCHAR or STRING fields in Hive
Date Mon, 16 Jan 2017 15:45:44 GMT
Few things that might have an effect:

1. Compression (better if you are in VARCHAR with finite length, instead of
a STRING)
2. Multicharset support (like NVARCHAR)
3. LOBs from RDBMS world are more suitable to be typecast to STRING for
pure text data (not images e.g.)

regards
Devopam

On Mon, Jan 16, 2017 at 9:07 PM, Mich Talebzadeh <mich.talebzadeh@gmail.com>
wrote:

>
> Coming from DBMS background I tend to treat the columns in Hive similar to
> an RDBMS table. For example if a table created in Hive as Parquet I will
> use VARCHAR(30) for column that has been defined as VARCHAR(30) as source.
> If a column is defined as TEXT in RDBMS table I use STRING in Hive with a
> max size of 2GB I believe.
>
> My view is that it is more efficient storage wise to have Hive table
> created as VARCHA as opposed to STRING.
>
> I have not really seen any performance difference if one uses VARCHAR or
> STRING. However, I believe there is a reason why one has VARCH in Hive as
> opposed to STRRING.
>
> What is the thread view on this?
>
> Thanks
>
>
> Dr Mich Talebzadeh
>
>
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-- 
Devopam Mittra
Life and Relations are not binary

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