But CLOB would limit what predicates and functions one could use on the
column, right?



*From:* Qifan Chen [mailto:[email protected]]
*Sent:* Thursday, May 26, 2016 5:43 AM
*To:* [email protected]
*Subject:* Re: Hive STRING and VARCHAR types



I wonder if we should consider the same length limit as Hive for a STRING
type, which is 2GB (http://www.folkstalk.com/2011/11/data-types-in-hive.html).
If so, the Trafodion mapping should be CLOB?



--Qifan



On Wed, May 25, 2016 at 11:49 PM, Selva Govindarajan <
[email protected]> wrote:

>From the Cloudera documentation

*Text table considerations:*

Text data files can contain values that are longer than allowed by the
VARCHAR(n) length limit. Any extra trailing characters are ignored when
Impala processes those values during a query

Will Trafodion behave the same way? Having the maximum limit for the
individual column provides the flexibility and optimal resource
utilization. However, having the limit in number of bytes for String and
number of characters for Varchar could be quite confusing for the user.

Selva





*From:* Hans Zeller [mailto:[email protected]]
*Sent:* Wednesday, May 25, 2016 6:12 PM
*To:* [email protected]
*Subject:* Hive STRING and VARCHAR types



Hi,



Here is a question on Hive data types. Ming is about to add support for
Hive VARCHAR data types, in addition to the existing STRING type, but we
hit a question we wanted to pose to the user community. Here is a proposed
type mapping from Hive to Trafodion:



*Hive type*

*Trafodion type*

*Max # of chars*

*Size in bytes*

*Existing/new*

*Comments*

STRING

VARCHAR(n BYTES)

n/4 to n

n

existing

n is determined by the HIVE_MAX_STRING_LENGTH CQD

VARCHAR(m)

VARCHAR(m)

m

4*m

proposed



Is it ok if we treat STRING and VARCHAR differently?



Thanks,


Ming and Hans





-- 

Regards, --Qifan

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