Sentinel Rapid Deployment has a command line option to connect to the PostgreSQL database:
Connect to the Sentinel Rapid Deployment server as the user who owns the Sentinel Rapid Deployment installation files.
Change to the Rapid Deployment bin directory.
cd <RD_install_home>/bin
Run the setenv.sh script to set the environment variables.
. setenv.sh
Change to the PostgreSQL bin directory.
cd <RD_install_home>/3rdparty/postgresq/bin
Run psql to connect to the PostgreSQL database.
./psql SIEM -U dbauser