Errors are generated when the OAI harvesting process is run. These are seen in application logs when the quartz trigger is run. This issue appears to be related to a null column constraint. Output trace is below.

2010-07-08 15:56:14,742 org.hibernate.util.JDBCExceptionReporter [ERROR]: ERROR: null value in column "repository_gateway_id" violates not-null constraint
2010-07-08 15:56:14,743 org.hibernate.event.def.AbstractFlushingEventListener [ERROR]: Could not synchronize database state with session
org.hibernate.exception.ConstraintViolationException: Could not execute JDBC batch update
        at org.hibernate.exception.SQLStateConverter.convert(SQLStateConverter.java:96)
        at org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:66)
        at org.hibernate.jdbc.AbstractBatcher.executeBatch(AbstractBatcher.java:275)
        at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:263)
        at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:179)
        at org.hibernate.event.def.AbstractFlushingEventListener.performExecutions(AbstractFlushingEventListener.java:321)
        at org.hibernate.event.def.DefaultFlushEventListener.onFlush(DefaultFlushEventListener.java:51)
        at org.hibernate.impl.SessionImpl.flush(SessionImpl.java:1206)
        at org.hibernate.impl.SessionImpl.managedFlush(SessionImpl.java:375)
        at org.hibernate.transaction.JDBCTransaction.commit(JDBCTransaction.java:137)
        at org.springframework.orm.hibernate3.HibernateTransactionManager.doCommit(HibernateTransactionManager.java:655)
        at org.springframework.transaction.support.AbstractPlatformTransactionManager.processCommit(AbstractPlatformTransactionManager.java:732)
        at org.springframework.transaction.support.AbstractPlatformTransactionManager.commit(AbstractPlatformTransactionManager.java:701)
        at org.springframework.transaction.support.TransactionTemplate.execute(TransactionTemplate.java:140)
        at eske.service.oai.harvester.impl.OaiHarvestingLogServiceImpl.storeHarvestingLog(OaiHarvestingLogServiceImpl.java:63)
        at eske.service.oai.harvester.impl.triplestore.TripleStoreOaiHarvesterServiceImpl.harvest(TripleStoreOaiHarvesterServiceImpl.java:105)
        at eske.service.oai.harvester.OAIHarvestingJobWrapper.harvest(OAIHarvestingJobWrapper.java:38)
        at sun.reflect.GeneratedMethodAccessor170.invoke(Unknown Source)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
        at java.lang.reflect.Method.invoke(Method.java:597)
        at org.springframework.util.MethodInvoker.invoke(MethodInvoker.java:276)
        at org.springframework.scheduling.quartz.MethodInvokingJobDetailFactoryBean$MethodInvokingJob.executeInternal(MethodInvokingJobDetailFactoryBean.java:260)
        at org.springframework.scheduling.quartz.QuartzJobBean.execute(QuartzJobBean.java:86)
        at org.quartz.core.JobRunShell.run(JobRunShell.java:202)
        at org.quartz.simpl.SimpleThreadPool$WorkerThread.run(SimpleThreadPool.java:525)
Caused by: java.sql.BatchUpdateException: Batch entry 0 insert into oai.harvesting_log (version, harvester_gateway_id, repository_gateway_id, date_harvested, date_from, date_until, num_records_requested, num_records_processed, num_records_inserted, num_records_skipped, num_records_deleted, num_records_error, status, metadata_format_id, id) values (0, 40b6d014-5c2b-4118-8cee-f34d10ec1d53, NULL, 2010-07-08 15:56:14.740000 -06:00:00, NULL, NULL, -1, 0, 0, 0, 0, 0, 0, 2, f2b40251-9506-4202-aa18-ceb71c9e894c) was aborted. Call getNextException to see the cause.
        at org.postgresql.jdbc2.AbstractJdbc2Statement$BatchResultHandler.handleError(AbstractJdbc2Statement.java:2537)
        at org.postgresql.core.v3.QueryExecutorImpl$1.handleError(QueryExecutorImpl.java:403)
        at org.postgresql.core.v3.QueryExecutorImpl.processResults(QueryExecutorImpl.java:1328)
        at org.postgresql.core.v3.QueryExecutorImpl.execute(QueryExecutorImpl.java:351)
        at org.postgresql.jdbc2.AbstractJdbc2Statement.executeBatch(AbstractJdbc2Statement.java:2674)
        at org.apache.commons.dbcp.DelegatingStatement.executeBatch(DelegatingStatement.java:297)
        at org.hibernate.jdbc.BatchingBatcher.doExecuteBatch(BatchingBatcher.java:70)
        at org.hibernate.jdbc.AbstractBatcher.executeBatch(AbstractBatcher.java:268)
        ... 22 more