Unit 2 : File System Flashcards
1
Q
Why database design is important? ( 4 )
A
- Define the database’s expected use
- Define different approaches needed for different types of databases
- Avoid redundant data
- Poorly designed database generates errors, which leads to bad decisions and then lead to failure of an organization
2
Q
List out 5 main components for a database system
A
- Hardware
- Software
- DBMS Software
- Operating System Software
- Application Programs and Utility Software
- People
- Procedures
- Data
3
Q
What are DBMS function （ 7 ）
A
- Data Dictionary Management
- Data Storage Management
- Data Transformation and Presentation
- Security Management
- Multiuser Access Control
- Backup and Recovery Management
- Data Integrity Management
4
Q
What is data redundancy?
A
- Data redundancy results in data inconsistency
- Means that diffrent and conflicting versions of the same data appear in different places
5
Q
Why managing data with file systems is obsolete? ( 6 )
A
- Time-consuming, as it was a high-level activity
- As number of files expands, system administration becomes difficult
- Making changes in current file structure is difficult
- File structure changes require modifications in all programs that use data in that file
- Modifications are likely to produce errors, requiring additional time to “debug” the program
- Security features hard to program and therefore often omitted
6
Q
What is a file system refers to ?
A
- Refers to a method for sttoring and managing files on a storage devices without the use of database management system
- Company stores customer name, sales, product in a excel file inside Sales folder, then employee, salaries in employees folder
7
Q
Why learning file system effects how we design our database? ( 3 )
A
- Understanding file system characteristics makes database design easier to understand
- Awareness of problems with file systems helps prevent similar problems in DBMS
- Knowledge of file systems is helpful if you plan to convert an obsolete file system to a DBMS
* More on notion
8
Q
How does manual file systems stores it’s data?
A
- Kept inside folders
9
Q
How does manual file systems organize their files?
A
- Organize based on data’s expected use ( ideally logically related )
10
Q
Manual file system is suitable in what condition? ( 2 )
A
- Small Amounts of Data
- Few Reporting Requirements
11
Q
What are the challenges when changing from file systems to computer system? ( 3 )
A
- Could be technically complex, requiring hiring of data processing ( DP ) specialitsts
- Resulted in numerous “home-grown” systems being created
- Initially, computer files were similar in design to manual files
- home-grown systems means that it was developed internally be a company’s IT team or DP specialists and with this reason, they often lacked standardization and difficult to integrate with other systems
12
Q
What is data anomalies?
A
- Issues or inconsistencies that occur in a database
13
Q
What condition usually creates data anomalies? ( 3 )
A
- Poorly designed database
- Non-normalized database
- Data Redundancy
14
Q
List out all the types of data anomalies ( 3 )
A
- Update Anomalies
- Occur when mading changes to existing records
- Insertion Anomalies
- Occur when entering new records
- Deletion Anomalies
- Occur when deleting records
15
Q
What are the structured compared with file system and database?
A
- File System
- Many separete and unrelated files
- Database
- Logically related data stored in a single logical data repository
