The ETL job (usually launched by the run_etl.nsh NSH Script Job) extracts, transforms, and loads data from the BMC Server Automation core database into the reports data warehouse. To see the detailed status of an ETL job process, launch the Metadata Navigator console by using the following URL: https://<ReportsServer>:9300/oracledimn/. The user is usually BL_READER. Drill down from the top level node. Green check marks indicate successful execution. Look for yellow or red check marks. You might need to dig down several levels. Click the "last" tasks to find the task during which a failure happened. You might be able to find a database-specific error, for example, running out of table space.
Contact your DBA to resolve the issue or contact BMC Support for more information.