In HEP experiments at LHC the database applications often become complex by reflecting the ever demanding requirements of the researchers. The ATLAS experiment has several Oracle DB clusters with over 216 database schemes each with its own set of database objects. To effectively monitor them, we designed a modern and portable application with exceptionally good characteristics. Some of them include: concise view of the most important DB metrics; top SQL statements based on CPU, executions, block reads, etc.; volume growth plots per schema and DB object type; database jobs section with signaling for problematic ones; in-depth analysis in case of contention on data or processes.