関連ワード:  what is database system in dbms    what is database management system in dbms    what is distributed database system in dbms    what is database system architecture in dbms    what is database system structure in dbms    what is database system environment in dbms    what is relational database system in dbms    what is data base management system dbms    what is the purpose of database system in dbms    what is relational database management system in dbms