[
https://issues.apache.org/jira/browse/HIVE-24777?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17284789#comment-17284789
]
Panagiotis Garefalakis commented on HIVE-24777:
-----------------------------------------------
cc: [~mustafaiman] [~zabetak][~kgyrtkirk]
> Standardize Hive's Type conversions
> -----------------------------------
>
> Key: HIVE-24777
> URL: https://issues.apache.org/jira/browse/HIVE-24777
> Project: Hive
> Issue Type: New Feature
> Reporter: Panagiotis Garefalakis
> Priority: Major
>
> Currently, Hive does some type safety checks looking for loosy type
> conversions such as: decimal to char, and long to varchar (even though not
> complete).
> These conversion are not documented and they might even differ depending on
> the CBO status. For example:
> {code:java}
> set hive.cbo.enable=false;
> create table comparison_table (col_v varchar(3), col_i int) stored as orc;
> insert into comparison_table values ('001', 15), ('002', 25), ('007', 75);
> select * from comparison_table where col_v >= 4L;
> // Converts to pred '4' to String
> // No result when CBO off
> set hive.cbo.enable=on;
> select * from comparison_table where col_v >= 4L;
> // Converts both to Double
> // 007 when CBO is on
> {code}
> Type conversions on the predicates also affect Sargs evaluation as in the
> first case (cbo off) string padding is missing, and in the latter case (cbo
> on) UDFBridge can no be evaluated.
> Finally, it seems that there are multiple configuration tracking the same
> thing:
> * hive.strict.timestamp.conversion
> * hive.strict.checks.type.safety
> This uber Jira is targeting the standardisation/documentation of these type
> checks and their conversions on Hive.
--
This message was sent by Atlassian Jira
(v8.3.4#803005)
