Amandeep,
I spoke w/ one of our Oracle DBA's and he suggested changing the query
statement as follows:
MySql Stmt:
select * from <<TABLE >> limit <splitlength> offset <splitstart>"
---------------------------------------------------------------
Oracle Stmt:
select *
from (select a.*,rownum rno
from (your_query_here must contain order by) a
where rownum <= splitstart + splitlength)
where rno >= splitstart;
This can be put into a function, but would require a type as well.
-----------------------------------------------------------------
If you edit org.apache.hadoop.mapred.lib.db.DBInputFormat, getSelectQuery, it
should work in Oracle
protected String getSelectQuery() {
... edit to include check for driver and create Oracle Stmt
return query.toString();
}
Brian
==================================================================
>> On Feb 5, 2009, at 11:37 AM, Stefan Podkowinski wrote:
>>
>>
>>> The 0.19 DBInputFormat class implementation is IMHO only suitable for
>>> very simple queries working on only few datasets. Thats due to the
>>> fact that it tries to create splits from the query by
>>> 1) getting a count of all rows using the specified count query (huge
>>> performance impact on large tables)
>>> 2) creating splits by issuing an individual query for each split with
>>> a "limit" and "offset" parameter appended to the input sql query
>>>
>>> Effectively your input query "select * from orders" would become
>>> "select * from orders limit <splitlength> offset <splitstart>" and
>>> executed until count has been reached. I guess this is not working sql
>>> syntax for oracle.
>>>
>>> Stefan
>>>
>>>
>>> 2009/2/4 Amandeep Khurana <ama...@gmail.com>:
>>>
>>>> Adding a semicolon gives me the error "ORA-00911: Invalid character"
>>>>
>>>> Amandeep
>>>>
>>>>
>>>> Amandeep Khurana
>>>> Computer Science Graduate Student
>>>> University of California, Santa Cruz
>>>>
>>>>
>>>> On Wed, Feb 4, 2009 at 6:46 AM, Rasit OZDAS <rasitoz...@gmail.com> wrote:
>>>>
>>>>
>>>>> Amandeep,
>>>>> "SQL command not properly ended"
>>>>> I get this error whenever I forget the semicolon at the end.
>>>>> I know, it doesn't make sense, but I recommend giving it a try
>>>>>
>>>>> Rasit
>>>>>
>>>>> 2009/2/4 Amandeep Khurana <ama...@gmail.com>:
>>>>>
>>>>>> The same query is working if I write a simple JDBC client and query the
>>>>>> database. So, I'm probably doing something wrong in the connection
>>>>>>
>>>>> settings.
>>>>>
>>>>>> But the error looks to be on the query side more than the connection
>>>>>>
>>>>> side.
>>>>>
>>>>>> Amandeep
>>>>>>
>>>>>>
>>>>>> Amandeep Khurana
>>>>>> Computer Science Graduate Student
>>>>>> University of California, Santa Cruz
>>>>>>
>>>>>>
>>>>>> On Tue, Feb 3, 2009 at 7:25 PM, Amandeep Khurana <ama...@gmail.com>
>>>>>>
>>>>> wrote:
>>>>>
>>>>>>> Thanks Kevin
>>>>>>>
>>>>>>> I couldnt get it work. Here's the error I get:
>>>>>>>
>>>>>>> bin/hadoop jar ~/dbload.jar LoadTable1
>>>>>>> 09/02/03 19:21:17 INFO jvm.JvmMetrics: Initializing JVM Metrics with
>>>>>>> processName=JobTracker, sessionId=
>>>>>>> 09/02/03 19:21:20 INFO mapred.JobClient: Running job: job_local_0001
>>>>>>> 09/02/03 19:21:21 INFO mapred.JobClient: map 0% reduce 0%
>>>>>>> 09/02/03 19:21:22 INFO mapred.MapTask: numReduceTasks: 0
>>>>>>> 09/02/03 19:21:24 WARN mapred.LocalJobRunner: job_local_0001
>>>>>>> java.io.IOException: ORA-00933: SQL command not properly ended
>>>>>>>
>>>>>>> at
>>>>>>>
>>>>>>>
>>>>> org.apache.hadoop.mapred.lib.db.DBInputFormat.getRecordReader(DBInputFormat.java:289)
>>>>>
>>>>>>> at org.apache.hadoop.mapred.MapTask.run(MapTask.java:321)
>>>>>>> at
>>>>>>>
>>>>>>> org.apache.hadoop.mapred.LocalJobRunner$Job.run(LocalJobRunner.java:138)
>>>>>>> java.io.IOException: Job failed!
>>>>>>> at
>>>>>>>
>>>>> org.apache.hadoop.mapred.JobClient.runJob(JobClient.java:1217)
>>>>>
>>>>>>> at LoadTable1.run(LoadTable1.java:130)
>>>>>>> at org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:65)
>>>>>>> at org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:79)
>>>>>>> at LoadTable1.main(LoadTable1.java:107)
>>>>>>> at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
>>>>>>> at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
>>>>>>> at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown
>>>>>>>
>>>>> Source)
>>>>>
>>>>>>> at java.lang.reflect.Method.invoke(Unknown Source)
>>>>>>> at org.apache.hadoop.util.RunJar.main(RunJar.java:165)
>>>>>>> at org.apache.hadoop.mapred.JobShell.run(JobShell.java:54)
>>>>>>> at org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:65)
>>>>>>> at org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:79)
>>>>>>> at org.apache.hadoop.mapred.JobShell.main(JobShell.java:68)
>>>>>>>
>>>>>>> Exception closing file
>>>>>>>
>>>>>>>
>>>>> /user/amkhuran/contract_table/_temporary/_attempt_local_0001_m_000000_0/part-00000
>>>>>
>>>>>>> java.io.IOException: Filesystem closed
>>>>>>> at
>>>>>>>
>>>>> org.apache.hadoop.hdfs.DFSClient.checkOpen(DFSClient.java:198)
>>>>>
>>>>>>> at
>>>>>>>
>>>>> org.apache.hadoop.hdfs.DFSClient.access$600(DFSClient.java:65)
>>>>>
>>>>>>> at
>>>>>>>
>>>>>>>
>>>>> org.apache.hadoop.hdfs.DFSClient$DFSOutputStream.closeInternal(DFSClient.java:3084)
>>>>>
>>>>>>> at
>>>>>>>
>>>>>>>
>>>>> org.apache.hadoop.hdfs.DFSClient$DFSOutputStream.close(DFSClient.java:3053)
>>>>>
>>>>>>> at
>>>>>>>
>>>>>>> org.apache.hadoop.hdfs.DFSClient$LeaseChecker.close(DFSClient.java:942)
>>>>>>> at org.apache.hadoop.hdfs.DFSClient.close(DFSClient.java:210)
>>>>>>> at
>>>>>>>
>>>>>>>
>>>>> org.apache.hadoop.hdfs.DistributedFileSystem.close(DistributedFileSystem.java:243)
>>>>>
>>>>>>> at
>>>>>>> org.apache.hadoop.fs.FileSystem$Cache.closeAll(FileSystem.java:1413)
>>>>>>> at org.apache.hadoop.fs.FileSystem.closeAll(FileSystem.java:236)
>>>>>>> at
>>>>>>>
>>>>>>> org.apache.hadoop.fs.FileSystem$ClientFinalizer.run(FileSystem.java:221)
>>>>>>>
>>>>>>>
>>>>>>> Here's my code:
>>>>>>>
>>>>>>> public class LoadTable1 extends Configured implements Tool {
>>>>>>>
>>>>>>> // data destination on hdfs
>>>>>>> private static final String CONTRACT_OUTPUT_PATH =
>>>>>>>
>>>>> "contract_table";
>>>>>
>>>>>>> // The JDBC connection URL and driver implementation class
>>>>>>>
>>>>>>> private static final String CONNECT_URL = "jdbc:oracle:thin:@dbhost
>>>>>>> :1521:PSEDEV";
>>>>>>> private static final String DB_USER = "user";
>>>>>>> private static final String DB_PWD = "pass";
>>>>>>> private static final String DATABASE_DRIVER_CLASS =
>>>>>>> "oracle.jdbc.driver.OracleDriver";
>>>>>>>
>>>>>>> private static final String CONTRACT_INPUT_TABLE =
>>>>>>> "OSE_EPR_CONTRACT";
>>>>>>>
>>>>>>> private static final String [] CONTRACT_INPUT_TABLE_FIELDS = {
>>>>>>> "PORTFOLIO_NUMBER", "CONTRACT_NUMBER"};
>>>>>>>
>>>>>>> private static final String ORDER_CONTRACT_BY_COL =
>>>>>>> "CONTRACT_NUMBER";
>>>>>>>
>>>>>>>
>>>>>>> static class ose_epr_contract implements Writable, DBWritable {
>>>>>>>
>>>>>>>
>>>>>>> String CONTRACT_NUMBER;
>>>>>>>
>>>>>>>
>>>>>>> public void readFields(DataInput in) throws IOException {
>>>>>>>
>>>>>>> this.CONTRACT_NUMBER = Text.readString(in);
>>>>>>>
>>>>>>> }
>>>>>>>
>>>>>>> public void write(DataOutput out) throws IOException {
>>>>>>>
>>>>>>> Text.writeString(out, this.CONTRACT_NUMBER);
>>>>>>>
>>>>>>>
>>>>>>> }
>>>>>>>
>>>>>>> public void readFields(ResultSet in_set) throws SQLException {
>>>>>>>
>>>>>>> this.CONTRACT_NUMBER = in_set.getString(1);
>>>>>>>
>>>>>>> }
>>>>>>>
>>>>>>> @Override
>>>>>>> public void write(PreparedStatement prep_st) throws SQLException
>>>>>>>
>>>>> {
>>>>>
>>>>>>> // TODO Auto-generated method stub
>>>>>>>
>>>>>>> }
>>>>>>>
>>>>>>> }
>>>>>>>
>>>>>>> public static class LoadMapper extends MapReduceBase
>>>>>>> implements Mapper<LongWritable,
>>>>>>> ose_epr_contract, Text, NullWritable> {
>>>>>>> private static final char FIELD_SEPARATOR = 1;
>>>>>>>
>>>>>>> public void map(LongWritable arg0, ose_epr_contract arg1,
>>>>>>> OutputCollector<Text, NullWritable> arg2, Reporter arg3)
>>>>>>> throws IOException {
>>>>>>>
>>>>>>> StringBuilder sb = new StringBuilder();
>>>>>>> ;
>>>>>>> sb.append(arg1.CONTRACT_NUMBER);
>>>>>>>
>>>>>>>
>>>>>>> arg2.collect(new Text (sb.toString()), NullWritable.get());
>>>>>>>
>>>>>>> }
>>>>>>>
>>>>>>> }
>>>>>>>
>>>>>>>
>>>>>>> public static void main(String[] args) throws Exception {
>>>>>>> Class.forName("oracle.jdbc.driver.OracleDriver");
>>>>>>> int exit = ToolRunner.run(new LoadTable1(), args);
>>>>>>>
>>>>>>> }
>>>>>>>
>>>>>>> public int run(String[] arg0) throws Exception {
>>>>>>> JobConf conf = new JobConf(getConf(), LoadTable1.class);
>>>>>>>
>>>>>>> conf.setInputFormat(DBInputFormat.class);
>>>>>>> DBConfiguration.configureDB(conf, DATABASE_DRIVER_CLASS,
>>>>>>> CONNECT_URL, DB_USER, DB_PWD);
>>>>>>>
>>>>>>> DBInputFormat.setInput(conf, ose_epr_contract.class,
>>>>>>> "select CONTRACT_NUMBER from OSE_EPR_CONTRACT",
>>>>>>> "select COUNT(CONTRACT_NUMBER) from OSE_EPR_CONTRACT");
>>>>>>> FileOutputFormat.setOutputPath(conf, new
>>>>>>> Path(CONTRACT_OUTPUT_PATH));
>>>>>>>
>>>>>>> conf.setMapperClass(LoadMapper.class);
>>>>>>> conf.setNumReduceTasks(0);
>>>>>>>
>>>>>>> conf.setOutputKeyClass(Text.class);
>>>>>>> conf.setOutputValueClass(NullWritable.class);
>>>>>>>
>>>>>>> JobClient.runJob(conf);
>>>>>>>
>>>>>>> return 0;
>>>>>>> }
>>>>>>> }
>>>>>>>
>>>>>>> -Amandeep
>>>>>>>
>>>>>>> Amandeep Khurana
>>>>>>> Computer Science Graduate Student
>>>>>>> University of California, Santa Cruz
>>>>>>>
>>>>>>>
>>>>>>> On Tue, Feb 3, 2009 at 6:51 PM, Kevin Peterson <kpeter...@biz360.com
>>>>>>>
>>>>>> wrote:
>>>>>>
>>>>>>>> On Tue, Feb 3, 2009 at 5:49 PM, Amandeep Khurana <ama...@gmail.com>
>>>>>>>> wrote:
>>>>>>>>
>>>>>>>>
>>>>>>>>> In the setInput(...) function in DBInputFormat, there are two sets
>>>>>>>>> of
>>>>>>>>> arguments that one can use.
>>>>>>>>>
>>>>>>>>> 1. public static void *setInput*(JobConf
>>>>>>>>>
>>>>>>>>> a) In this, do we necessarily have to give all the fieldNames (which
>>>>>>>>>
>>>>> are
>>>>>
>>>>>>>>> the
>>>>>>>>> column names right?) that the table has, or do we need to specify
>>>>>>>>>
>>>>> only
>>>>>
>>>>>>>> the
>>>>>>>>
>>>>>>>>> ones that we want to extract?
>>>>>>>>>
>>>>>>>> You may specify only those columns that you are interested in.
>>>>>>>>
>>>>>>>> b) Do we have to have a orderBy or not necessarily? Does this relate
>>>>>>>> to
>>>>>>>> the
>>>>>>>>
>>>>>>>>> primary key in the table in any ways?
>>>>>>>>>
>>>>>>>> Conditions and order by are not necessary.
>>>>>>>>
>>>>>>>> a) Is there any restriction on the kind of queries that this function
>>>>>>>>
>>>>>>>>> can take in the inputQuery string?
>>>>>>>>>
>>>>>>>> I don't think so, but I don't use this method -- I just use the
>>>>>>>>
>>>>> fieldNames
>>>>>
>>>>>>>> and tableName method.
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>>> I am facing issues in getting this to work with an Oracle database
>>>>>>>>>
>>>>> and
>>>>>
>>>>>>>>> have no idea of how to debug it (an email sent earlier).
>>>>>>>>> Can anyone give me some inputs on this please?
>>>>>>>>>
>>>>>>>> Create a new table that has one column, put about five entries into
>>>>>>>>
>>>>> that
>>>>>
>>>>>>>> table, then try to get a map job working that outputs the values to a
>>>>>>>>
>>>>> text
>>>>>
>>>>>>>> file. If that doesn't work, post your code and errors.
>>>>>>>>
>>>>>>>>
>>>>>>>
>>>>>
>>>>> --
>>>>> M. Raşit ÖZDAŞ
>>>>>
>>>>>
>>
>
>
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