Rajesh Balamohan created HIVE-26507:
---------------------------------------

             Summary: Iceberg: In place metadata generation may not work for 
certain datatypes
                 Key: HIVE-26507
                 URL: https://issues.apache.org/jira/browse/HIVE-26507
             Project: Hive
          Issue Type: Bug
            Reporter: Rajesh Balamohan


"alter table" statements can be used for generating iceberg metadata 
information (i.e for converting external tables  -> iceberg tables).

As part of this process, it also converts certain datatypes to iceberg 
compatible types (e.g char -> string). "iceberg.mr.schema.auto.conversion" 
enables this conversion.

This could cause certain issues at runtime. Here is an example
{noformat}

Before conversion:
==================
-- external table
select count(*) from customer_demographics where cd_gender = 'F' and 
cd_marital_status = 'U' and cd_education_status = '2 yr Degree';

27440

after conversion:
=================
-- iceberg table
select count(*) from customer_demographics where cd_gender = 'F' and 
cd_marital_status = 'U' and cd_education_status = '2 yr Degree';

0

select count(*) from customer_demographics where cd_gender = 'F' and 
cd_marital_status = 'U' and trim(cd_education_status) = '2 yr Degree';

27440
 {noformat}
 



--
This message was sent by Atlassian Jira
(v8.20.10#820010)

Reply via email to