File-Based System Limitations(1)

• Separation and isolation of data

• 跨檔案查詢不易（課程、學生、選課，誰沒選到必修課？）

• Duplication of data 姓名、住址、電話

• Wasteful, loss data integrity

• Data dependence

• AP must be changed with Data format

• Incompatible file format

• C and COBOL

• Queries fixed by AP (program & developer)