volume_mute
Which one of these tables is likely to raise changes in its accessing programs?
publish date: 2022/08/26 06:41:00 GMT+10
volume_mute
- (Table A) Student record structure definition in a traditional file process application
| Date Item Name | Starting Position in Record | Length in Characters (bytes) |
|
Name |
1 | 30 |
| Student_Number | 31 | 4 |
| Class | 35 | 1 |
| Major | 36 | 4 |
- (Table B) Student record structure definition in DBMS
| Column_Name | Data_type | Belongs_to_Relation |
| Name | Character(30) | Student |
| Student_number | Character(4) | Student |
| Class | Integer(1) | Student |
| Major | Major_type | Student |
Correct Answer
Table A
Explanation
A file access program may be written in such a way that it can access only STUDENT records of the structure shown in Table A. If we want to add another piece of data to each STUDENT record, say the Birth_date, such a program will no longer work and must be changed. By contrast, in a DBMS environment, we only need to change the description of STUDENT records in the catalog (Table B) to reflect the inclusion of the new data item Birth_date; no programs are changed. The next time a DBMS program refers to the catalog, the new structure of STUDENT records will be accessed and used.
Reference
Fundamentals of database systems (7th edition)