DB QA

1. Bert the Payroll Guy is about to retire after 40 years and it’s time to replace his manual time card system with some sort of computerized database. You have been asked to come up with the database design. As best we can tell, the time card system has the following properties: properties: • A timecard contains hours worked and date submitted • Each timecard is associated with exactly one employee • Each timecard has a unique id • Each timecard has a status: approved, not approved, or pending (not ex amined yet) • Each Each employee has a name, address, and a unique id • Each employee submits a time card every pay period. period. i.e. In 1 year, they will submit multiple time cards • Each employee is associated with exactly one manager • Each manager is al so an employee • Each Each manager is in charge of one or more employees • Each manager approves time cards for one or more employees Draw an ER diagram that captures this information.

2. List five disadvantages of file processing systems.  PROGRAM-DATA DEPENDENCE : File descriptions are stored within each database application program that accesses a given file  DUPLICATIO N OF DATA : Because applications are often developed independently in file processing systems, unplanned duplicate data files are the rule rather than the exception.  LIMITED DATA SHARING : With the traditional file processing approach, each application has its own private files, and users have little opportunity to share data outside their own applications.  LENGTHY DEVELOPMENT TIMES : With traditional file processing systems, each new application requires that the developer essentially start from scratch by designing new file formats and descriptions and then writing the file access logic for each new program.  EXCESSIVE PROGRAM MAINTENANCE : The preceding factors all combined to create a heavy program maintenance load in organizations that relied on traditional file processing systems.