Atomicity: Either all functions are laid out or none are. Users could not have to think about the effect of incomplete operations. DBMS ensures this by undoing the functions of incomplete operations.

 Aggregation: A concept which is needed to model a relationship between relationships and a collection of entities. It is used when we require express a relationship among relationships.

Name the three major groups of files on disk that devolve a database in Oracle There are three major groups of files on disk that devolve a database.

• Database files
• Control files
• Redo logs

 The most important of these are the database folders where the actual data insides. The control files and the redo logs support the properties of the architecture itself. All three groups of files must be open, present, and available to Oracle for any data on the database to be utilized. Without these files, you cannot operate the database, and the database administrator has to answer some or the entire database needs a backup, if there is one.