In a default Qlik Sense installation, a Qlik Sense Repository Database (QRD) service is created specifically for use by the Qlik Sense Repository Service (QRS). The QRS connects to the QRD to read and write data in the repository database. A PostgreSQL database is used by default.
In a default Qlik Sense installation, the Qlik Sense Repository Database (QRD) service must be started before the rest of the Qlik Sense services.