We have a similar situation like this in production…for your case case I would
propose the following steps
1. Design a map reduce job (Job Output format - Text, Lzo, Snappy, your choice)
Inputs to Mapper
-- records from these three feeds
Outputs from Mapper
-- Key = <EMP1> Value = <feed1~field1 field2 field6 field9>
-- Key = <EMP1> Value = <feed2~field5 field7 field10>
-- Key = <EMP1> Value = <feed3~field3 field4 field8>
Reducer Output
-- Key = <EMP1> Value = <field1 field2 field3 field4 field5 field6
field7 field8 field9 field10>
2. (Optional) If u use LZO then u will need to run LzoIndexer
3. CREATE TABLE IF NOT EXISTS YOUR_HIVE_TABLE
4. ALTER TABLE ADD PARTITION (foo1 = , foo2 = ) LOCATION 'path/to/files'
From: Stephen Sprague <[email protected]<mailto:[email protected]>>
Reply-To: "[email protected]<mailto:[email protected]>"
<[email protected]<mailto:[email protected]>>
Date: Friday, July 26, 2013 4:37 PM
To: "[email protected]<mailto:[email protected]>"
<[email protected]<mailto:[email protected]>>
Subject: Re: Merging different HDFS file for HIVE
i like #2.
so you have three, say, external tables representing your three feed files.
After the third and final file is loaded then join 'em all together - maybe
make the table partitioned for one per day.
for example:
alter table final add partition (datekey=YYYYMMDD);
insert overwrite table final partition (datekey=YYYYMMDD) select
EMP_ID,f1,...,f10 from FF1 a join FF2 b on (a.EMP_ID=b.EMP_ID join FF3 c on
(b.EMP_ID=c.EMP_ID)
Or a variation on #3. make a view on the three tables which would look just
like the select statement above.
What do you want to optimize for?
On Fri, Jul 26, 2013 at 5:30 AM, Nitin Pawar
<[email protected]<mailto:[email protected]>> wrote:
Option 1 ) Use pig or oozie, write a workflow and join the files to a single
file
Option 2 ) Create a temp table for each of the different file and then join
them to a single table and delete temp table
Option 3 ) don't do anything, change your queries to look at three different
files when they query about different files
Wait for others to give better suggestions :)
On Fri, Jul 26, 2013 at 4:22 PM, Ramasubramanian Narayanan
<[email protected]<mailto:[email protected]>>
wrote:
Hi,
Please help in providing solution for the below problem... this scenario is
applicable in Banking atleast...
I have a HIVE table with the below structure...
Hive Table:
Field1
...
Field 10
For the above table, I will get the values for each feed in different file. You
can imagine that these files belongs to same branch and will get at any time
interval. I have to load into table only if I get all 3 files for the same
branch. (assume that we have a common field in all the files to join)
Feed file 1 :
EMP ID
Field 1
Field 2
Field 6
Field 9
Feed File2 :
EMP ID
Field 5
Field 7
Field 10
Feed File3 :
EMP ID
Field 3
Field 4
Field 8
Now the question is,
what is the best way to make all these files to make it as a single file so
that it can be placed under the HIVE structure.
regards,
Rams
--
Nitin Pawar
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