Sqoop import without split by

Question

I'm trying to import a Teradata table which has a composite key as primary key. Hence setting the --num mapper 1 and running it without the --split-by parameter. However, I am running into the following issue. Please help.

Error: java.io.IOException: SQLException in nextKeyValue
    at org.apache.sqoop.mapreduce.db.DBRecordReader.nextKeyValue(DBRecordReader.java:277)
    at org.apache.hadoop.mapred.MapTask$NewTrackingRecordReader.nextKeyValue(MapTask.java:556)
    at org.apache.hadoop.mapreduce.task.MapContextImpl.nextKeyValue(MapContextImpl.java:80)
    at org.apache.hadoop.mapreduce.lib.map.WrappedMapper$Context.nextKeyValue(WrappedMapper.java:91)
    at org.apache.hadoop.mapreduce.Mapper.run(Mapper.java:145)
    at org.apache.sqoop.mapreduce.AutoProgressMapper.run(AutoProgressMapper.java:64)
    at org.apache.hadoop.mapred.MapTask.runNewMapper(MapTask.java:787)
    at org.apache.hadoop.mapred.MapTask.run(MapTask.java:341)
    at org.apache.hadoop.mapred.YarnChild$2.run(YarnChild.java:168)
    at java.security.AccessController.doPrivileged(Native Method)
    at javax.security.auth.Subject.doAs(Subject.java:422)
    at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1709)
    at org.apache.hadoop.mapred.YarnChild.main(YarnChild.java:162)
Caused by: com.teradata.jdbc.jdbc_4.util.JDBCException: [Teradata Database] [TeraJDBC 14.00.00.01] [Error 3707] [SQLState 42000] Syntax error, expected something like a name or a Unicode delimited identifier between the word 'Record' and the 'Start' keyword.
    at com.teradata.jdbc.jdbc_4.util.ErrorFactory.makeDatabaseSQLException(ErrorFactory.java:307)
    at com.teradata.jdbc.jdbc_4.statemachine.ReceiveInitSubState.action(ReceiveInitSubState.java:102)
    at com.teradata.jdbc.jdbc_4.statemachine.StatementReceiveState.subStateMachine(StatementReceiveState.java:298)
    at com.teradata.jdbc.jdbc_4.statemachine.StatementReceiveState.action(StatementReceiveState.java:179)
    at com.teradata.jdbc.jdbc_4.statemachine.StatementController.runBody(StatementController.java:120)
    at com.teradata.jdbc.jdbc_4.statemachine.StatementController.run(StatementController.java:111)
    at com.teradata.jdbc.jdbc_4.TDStatement.executeStatement(TDStatement.java:372)
    at com.teradata.jdbc.jdbc_4.TDStatement.prepareRequest(TDStatement.java:541)
    at com.teradata.jdbc.jdbc_4.TDPreparedStatement.<init>(TDPreparedStatement.java:96)
    at com.teradata.jdbc.jdk6.JDK6_SQL_PreparedStatement.<init>(JDK6_SQL_PreparedStatement.java:21)
   at com.teradata.jdbc.jdk6.JDK6_SQL_Connection.constructPreparedStatement(JDK6_SQL_Connection.java:76)
    at com.teradata.jdbc.jdbc_4.TDSession.prepareStatement(TDSession.java:1491)
    at org.apache.sqoop.mapreduce.db.DBRecordReader.executeQuery(DBRecordReader.java:101)

Answer 1

you will have to use --split-by OR --boundary-query option, regardless of --num-mappers OR -m option.

Split column is not necessarily equal to PK. You can have complex PK and some int Split column. but use one of the column from composite key as --split-by option.

--split-by ~~> Column of the table used to split work units

also try --boundry-query + --split-by if above option (only --split-by) doesn't work:

  sqoop import \
  --connect "jdbc:mysql://quickstart.cloudera:3306/retail_db" \
  --username=retail_dba \
  --password=cloudera \
  --table departments \
  --target-dir /user/cloudera/departments \
  -m 2 \
  --boundary-query "select 2, 8 from departments limit 1" \
  --split-by department_id

By default sqoop will use query select min(<split-by>), max(<split-by>) from <table name> to find out boundaries for creating splits. In some cases this query is not the most optimal so you can specify any arbitrary query returning two numeric columns using --boundary-query argument.

Check detail explanation here: https://stackoverflow.com/a/37389134/2079249

selecting_the_data_to_import

Answer 2

Try using -m1 in your sqoop command instead of -- num mapper 1.