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https://issues.apache.org/jira/browse/HIVE-718?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12744143#action_12744143
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Todd Lipcon commented on HIVE-718:
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Prasad: this is true, but the atomicity issue was already there - we just
discovered it while looking at this section of the code. My guess is that there
are similar bugs elsewhere in Hive - there's no safe way to have multiple
threads compete for a directory name, so really any movement of files has to be
coordinated by the metastore to be safe. The hadoop-side issues are:
- mkdirs on an existing directory will return the exact same thing as mkdirs on
one that didn't previously exist
- rename of one directory to a new name will not give an error if the new name
exists - rather, it will move your directory inside that one
- checking if (not exists) { do something to a location } is obviously racy
> Load data inpath into a new partition without overwrite does not move the file
> ------------------------------------------------------------------------------
>
> Key: HIVE-718
> URL: https://issues.apache.org/jira/browse/HIVE-718
> Project: Hadoop Hive
> Issue Type: Bug
> Affects Versions: 0.4.0
> Reporter: Zheng Shao
> Attachments: HIVE-718.1.patch, HIVE-718.2.patch, hive-718.txt
>
>
> The bug can be reproduced as following. Note that it only happens for
> partitioned tables. The select after the first load returns nothing, while
> the second returns the data correctly.
> insert.txt in the current local directory contains 3 lines: "a", "b" and "c".
> {code}
> > create table tmp_insert_test (value string) stored as textfile;
> > load data local inpath 'insert.txt' into table tmp_insert_test;
> > select * from tmp_insert_test;
> a
> b
> c
> > create table tmp_insert_test_p ( value string) partitioned by (ds string)
> > stored as textfile;
> > load data local inpath 'insert.txt' into table tmp_insert_test_p partition
> > (ds = '2009-08-01');
> > select * from tmp_insert_test_p where ds= '2009-08-01';
> > load data local inpath 'insert.txt' into table tmp_insert_test_p partition
> > (ds = '2009-08-01');
> > select * from tmp_insert_test_p where ds= '2009-08-01';
> a 2009-08-01
> b 2009-08-01
> d 2009-08-01
> {code}
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