모든 mode에서 in-memory(temporary:Application의 주기를 따름) / disk-based(persistent) 가능
: jdbc url setting에서 설정 가능(in-memory로 쓸 경우에만 명시하는듯)
Connection Mode
1) Embedded mode (local connections using JDBC)
2) Server mode (remote connections using JDBC or ODBC over TCP/IP)
3) Mixed mode (local and remote connections at the same time)