[
https://issues.apache.org/jira/browse/HIVE-2615?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13159720#comment-13159720
]
David Phillips commented on HIVE-2615:
--------------------------------------
I see this as three different issues:
# The NULL literal produces a VOID type.
# Tables with a VOID type cannot be queried at all.
# Queries for tables with a VOID type fail at execution time rather than
compile time.
Some potential solutions:
# Treat a VOID type as always being NULL. This is a non-backwards-compatible
object inspector change that require changes all over the place, including
third party code.
# Pick a type for a NULL literal in CTAS. There is no obvious choice for the
type, but STRING seems like the best option.
# Have the CTAS error out at compile time with a hint for the user to use CAST
to specify the type.
> CTAS with literal NULL creates VOID type
> ----------------------------------------
>
> Key: HIVE-2615
> URL: https://issues.apache.org/jira/browse/HIVE-2615
> Project: Hive
> Issue Type: Bug
> Reporter: David Phillips
>
> Create the table with a column that always contains NULL:
> {quote}
> hive> create table bad as select 1 x, null z from dual;
> {quote}
> Because there's no type, Hive gives it the VOID type:
> {quote}
> hive> describe bad;
> OK
> x int
> z void
> {quote}
> This seems weird, because AFAIK, there is no normal way to create a column of
> type VOID. The problem is that the table can't be queried:
> {quote}
> hive> select * from bad;
> OK
> Failed with exception java.io.IOException:java.lang.RuntimeException:
> Internal error: no LazyObject for VOID
> {quote}
> Worse, even if you don't select that field, the query fails at runtime:
> {quote}
> hive> select x from bad;
> ...
> FAILED: Execution Error, return code 2 from
> org.apache.hadoop.hive.ql.exec.MapRedTask
> {quote}
--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators:
https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa
For more information on JIRA, see: http://www.atlassian.com/software/jira
