john created HIVE-7853:
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Summary: OrcNewInputFormat
Key: HIVE-7853
URL: https://issues.apache.org/jira/browse/HIVE-7853
Project: Hive
Issue Type: Bug
Components: File Formats
Affects Versions: 0.13.1
Environment: all
Reporter: john
Key is null in map when OrcNewInputFormat is used as Input Format Class
When using OrcNewInputFormat as input format class for my map reduce job, I
find its key is always null in my map method. This gives me no way to get row
number in my map method. If you compare RCFileInputFormat (for RC file), its
key in map method returns the row number so I know which row I am processing.
Is there any workaround for me to get the row number from my map method? Of
course, I can count the row number by myself. But that has two problems: #1 I
have to assume the row is coming in the order; #2 I will get duplicated (and
wrong) row numbers if a big input file causes multiple file splits (which will
trigger my map method multiple times in different data nodes). At this point,
I am really seeking a better way to get row number for each processed row in
map method.
Here is what I have in my map logs:
[2014-08-06 09:39:25 DEBUG com.xxxx.hadoop.orcfile.OrcFileMap]: Mapper
Input Key: (null)
[2014-08-06 09:39:25 DEBUG com.xxxx.hadoop.orcfile.OrcFileMap]: Mapper
Input Value: {Q81510000, T99760000, 699760000, 81567560000, 9667981610000,
978989898980000, Laura, laura...@gmail.com}
My map method is:
protected void map(Object key, Writable value, Context context)
throws IOException, InterruptedException {
logger.debug("Mapper Input Key: " + key);
logger.debug("Mapper Input Value: " + value.toString());
.....
}
The fix should be: add following statement in nextKeyValue() method and pass
the result all the way up to the map() method as its key:
reader.getRowNumber();
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