I am using serde in hive to store data into hive table from xml file.
Whenever I retrieve data using command select * from table it give all records
from table.
But when I want to extract an individual column it gives error .
Please Tell me how can I retrieve a single column from this table.
This is the error when I try to extract a single column from hive serde table .
java.lang.RuntimeException: java.lang.reflect.InvocationTargetException
at
org.apache.hadoop.hive.shims.Hadoop20SShims$CombineFileRecordReader.initNextRecordReader(Hadoop20SShims.java:306)
at
org.apache.hadoop.hive.shims.Hadoop20SShims$CombineFileRecordReader.<init>(Hadoop20SShims.java:269)
at
org.apache.hadoop.hive.shims.Hadoop20SShims$CombineFileInputFormatShim.getRecordReader(Hadoop20SShims.java:366)
at
org.apache.hadoop.hive.ql.io.CombineHiveInputFormat.getRecordReader(CombineHiveInputFormat.java:413)
at org.apache.hadoop.mapred.MapTask.runOldMapper(MapTask.java:371)
at org.apache.hadoop.mapred.MapTask.run(MapTask.java:325)
at org.apache.hadoop.mapred.Child$4.run(Child.java:270)
at java.security.AccessController.doPrivileged(Native Method)
at javax.security.auth.Subject.doAs(Subject.java:396)
at
org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1127)
at org.apache.hadoop.mapred.Child.main(Child.java:264)
Caused by: java.lang.reflect.InvocationTargetException
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at
sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39)
at
sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)
at java.lang.reflect.Constructor.newInstance(Constructor.java:513)
at
org.apache.hadoop.hive.shims.Hadoop20SShims$CombineFileRecordReader.initNextRecordReader(Hadoop20SShims.java:292)
... 10 more
Caused by: java.lang.NullPointerException
at
org.apache.hadoop.hive.contrib.serde2.XmlInputFormat$XmlRecordReader.<init>(XmlInputFormat.java:76)
at
org.apache.hadoop.hive.contrib.serde2.XmlInputFormat.getRecordReader(XmlInputFormat.java:44)
at
org.apache.hadoop.hive.ql.io.CombineHiveRecordReader.<init>(CombineHiveRecordReader.java:68)
... 15 more
From: Nitin Pawar [mailto:nitinpawar...@gmail.com]
Sent: Monday, December 17, 2012 1:54 PM
To: user@hive.apache.org
Subject: Re: reg : reteriveing a single column from hive serde table
select * will just hdfs cat your file
when you are using serde, do you have column separator in place? if not can you
do select * from table limit 1
to get normally a single coulmn you should do select column from table where
column=value
On Mon, Dec 17, 2012 at 1:51 PM, Mohit Chaudhary01
<mohit_chaudhar...@infosys.com<mailto:mohit_chaudhar...@infosys.com>> wrote:
Hi
I am using serde in hive to store data into hive table from xml file.
Whenever I retrieve data using command select * from table it give all records
from table.
But when I want to extract an individual column it gives error .
Please Tell me how can I retrieve a single column from this table.
Thanks
Mohit chaudhary
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