How to use Oracle Direct Connector for HDFS(DCH)?

Question

hi all,
I am trying to use Oracle database to access HDFS through DCH. Now I installed Oracle database 11.2, hadoop-0.20.2 and DCH on the same linux machine.
I also configured hdfs_stream properly and created Oracle directory HDFS_BIN_PATH according to README.txt file within DCH.
Now I encountered a problem, how I create a external table which access data residing on HDFS?
Can anyone help me ?
Thanks in advance.
Chopsun
Edited by: user1745344 on 2012-5-21 下午11:30

Answer 1

I figure out the way which access HDFS data from Oracle External Table through DCH as below, but still face some problems
Step 1
Created Oracle directories as following:
CREATE OR REPLACE DIRECTORY hdfs_bin_path AS '/home/oracle/orahdfs/bin';
CREATE OR REPLACE DIRECTORY data_dir AS '/user/hadoop';
where /user/hadoop is HDFS directory in which data file test.txt located.
Step 2
Created Oracle external table as following:
create table xqs_ext_test(col1 varchar2(100))
organization external (
TYPE oracle_loader
DEFAULT DIRECTORY data_dir
ACCESS PARAMETERS (
records delimited by newline
preprocessor hdfs_bin_path:'hdfs_stream'
badfile hdfs_bin_path:'empxt%a_%p.bad'
logfile hdfs_bin_path:'empxt%a_%p.log'
fields terminated by ','
LOCATION ('test.txt'))
reject limit unlimited
parallel 2;
when run SQL statement : select * from xqs_ext_test; the following error was prompted:
SELECT * FROM xqs_ext_test
ERROR at line 1:
ORA-29913: error in executing ODCIEXTTABLEOPEN callout
ORA-29400: data cartridge error
KUP-04040: file test.txt in DATA_DIR not found
who can help me out with this problem?
Best Regards
Chopsun
Edited by: user1745344 on 2012-5-22 上午1:02