[
https://issues.apache.org/jira/browse/HIVE-6016?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Sushanth Sowmyan updated HIVE-6016:
-----------------------------------
Description:
Prashant and I discovered that the implementation of the wrapping Iterator in
listLocatedStatus at
https://github.com/apache/hive/blob/2d2f89c21618341987c1257a88691981f1f606c7/shims/src/0.23/java/org/apache/hadoop/hive/shims/Hadoop23Shims.java#L350-L393
is broken.
Basically, if you had files (a,b,_s) , with a filter that is supposed to filter
out _s, we expect an output result of (a,b). Instead, we get (a,b,null), with
hasNext looking at the next value to see if it's null, and using that to decide
if it has any more entries, and thus, (a,b,_s) becomes (a,b).
There's a boundary condition on the very first pick, which causes a (_s,a,b) to
result in (_s,a,b), bypassing the filter, and thus, we wind up with a resultant
unfiltered (_s,a,b) which orc breaks on.
was:
Prashant and I discovered that the implementation of the wrapping Iterator in
listLocatedStatus at
https://github.com/apache/hive/blob/2d2f89c21618341987c1257a88691981f1f606c7/shims/src/0.23/java/org/apache/hadoop/hive/shims/Hadoop23Shims.java#L350-L393
is broken.
Basically, if you had files (a,b,_s) , with a filter that is supposed to filter
out _s, we expect an output result of (a,b). Instead, we get (a,b,null), with
hasNext looking at the next value to see if it's null, and using that to decide
if it has any more entries, and thus, (a,b,_s) becomes (a,b).
The problem with this approach, however, is that if you have an underlying
(a,_s,b) and expect a (a,b) from it, you won't, because it translates to a
(a,null,b), which then translates to a (a).
Furthermore, there's a boundary condition on the very first pick, which causes
a (_s,a,b) to result in (_s,a,b), bypassing the filter, and thus, we wind up
with a resultant unfiltered (_s,a,b) which orc breaks on.
> Hadoop23Shims has a bug in listLocatedStatus impl.
> --------------------------------------------------
>
> Key: HIVE-6016
> URL: https://issues.apache.org/jira/browse/HIVE-6016
> Project: Hive
> Issue Type: Bug
> Components: Shims
> Affects Versions: 0.13.0
> Reporter: Sushanth Sowmyan
> Assignee: Prasanth J
> Attachments: HIVE-6016.1.patch
>
>
> Prashant and I discovered that the implementation of the wrapping Iterator in
> listLocatedStatus at
> https://github.com/apache/hive/blob/2d2f89c21618341987c1257a88691981f1f606c7/shims/src/0.23/java/org/apache/hadoop/hive/shims/Hadoop23Shims.java#L350-L393
> is broken.
> Basically, if you had files (a,b,_s) , with a filter that is supposed to
> filter out _s, we expect an output result of (a,b). Instead, we get
> (a,b,null), with hasNext looking at the next value to see if it's null, and
> using that to decide if it has any more entries, and thus, (a,b,_s) becomes
> (a,b).
> There's a boundary condition on the very first pick, which causes a (_s,a,b)
> to result in (_s,a,b), bypassing the filter, and thus, we wind up with a
> resultant unfiltered (_s,a,b) which orc breaks on.
--
This message was sent by Atlassian JIRA
(v6.1.4#6159)
