Dear students of Database Systems' Classes (BA02 & BB02),
Below is a list of questions for your online quizz. Each of you only needs to choose a question and then answer it as soon as possible. You may not choose and answer a question which has been taken and answered by someone (thus redundant answers are not allowed). Please be the first as you will have a greater freedom to choose a question as your preference. If you become the last one to answer then you will not have a choice any more.
List of questions:
Advanced Normalization
1. Describe the purpose of using inference rules to identify functional dependencies for a given relation.
2. Describe the purpose of Armstrong’s axioms.
3. Discuss the purpose of Boyce–Codd Normal Form (BCNF) and discuss how BCNF differs from 3NF. Provide an example to illustrate your answer.
4. Describe the concept of multi-valued dependency and discuss how this concept relates to 4NF. Provide an example to illustrate your answer.
5. Describe the concept of join dependency and discuss how this concept relates to 5NF. Provide an example to illustrate your answer.
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Enahanced-Entity Relationship Modeling
6. Describe the relationship between a superclass and its subclass.
7. Describe and illustrate using an example the process of attribute inheritance.
8. What are the main reasons for introducing the concepts of superclasses and subclasses into an ER model?
9. Describe what a shared subclass represents and how this concept relates to multiple inheritance.
10. Describe and contrast the process of specialization with the process of generalization.
11. Describe the two main constraints that apply to a specialization/generalization relationship.
12. Describe and contrast the concepts of aggregation and composition and provide an example of each.
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Distributed DBMS
13. Explain what is meant by a DDBMS and discuss the motivation in providing such a system.
14. Compare and contrast a DDBMS with distributed processing. Under what circumstances would you choose a DDBMS over distributed processing?
15. Compare and contrast a DDBMS with a parallel DBMS. Under what circumstances would you choose a DDBMS over a parallel DBMS?
16. Discuss the advantages and disadvantages of a DDBMS.
17. What is the difference between a homogeneous and a heterogeneous DDBMS? Under what circumstances would such systems generally arise?
18. What are the strategic objectives for the definition and allocation of fragments?
19. What is a multidatabase system? Describe a reference architecture for such a system.
20. Explain the term ‘non-blocking protocol’ and explain why the two-phase commit protocol is not a non-blocking protocol.
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Web Technologies and DBMS
21. What are Web services? Give some examples of Web services.
22. Describe the advantages and disadvantages of the Web as a database platform.
23. Describe the Common Gateway Interface and server extensions, as approaches for integrating databases on to the Web.
24. Describe how cookies can be used to store information about a user.
25. Describe the differences between ASP and JSP.
26. Describe the differences between the ADO Recordset and the ADO.NET Dataset.
27. Describe the components of Oracle’s Web Platform.
Rules:
1. You may answer in the comment field below or at binusmaya forum
2. Only high quality answer will be rewarded 10 points for your final exam.
3. Deadline is 7th June 2015.
Jonathan Gunawan 1701297684 bb02
ReplyDelete25.the difference between ASP and JSP
ASP:
1. Asp stands for Active Server Pages
2. ASP is released by Microsoft
3. ASP uses visual basic language
4. ASP application can be connected to MS SQL and MS Access database
5. Microsoft IIS Server supports ASP on windows
6. ASP is not a free language because ASP relies on windows and IIS that both of them are not free
7. ASP code can be interpreted
JSP:
1. JSP stands for java server pages
2. JSP I s released by SUN microsystems
3. JSP is java based language
4. JSP can be connected to any database by loading the appropriate driver
5. JSP supported by apache tomcat web server and linux based server support the website built using JSP
6. JSP is available for free
7. JSP code can be interpreted also compiled
Aldo Makmur 1701316273 BB02
ReplyDelete16. Discuss the advantages and disadvantages of a DDBMS.
Advantages of DDBMS:
1. Faster data processing.
Distributed DB system spreads out the systems workload by processing data at several sites.
2. Data are located near the greatest demand site.
Data in a distributed database system are dispersed to match business requirements which will reduce the cost of data access.
3. Faster data access.
End users often work with only a locally stored subset of the company’s data.
4. Growth facilitation.
New sites can be added to the network without affecting the operations of other sites.
5. Improved communications.
Because local sites are smaller and located closer to customers, local sites foster better communication among departments and between customers and company staff.
6. Reduced operating costs.
It is more cost-effective to add workstations to a network than to update a mainframe system. Development work is done more cheaply and more quickly on low-cost PCs than on mainframes.
7. User-friendly interface.
PCs and workstations are usually equipped with an easy-to-use graphical user interface (GUI). The GUI simplifies training and use for end users.
8. Less danger of a single-point failure.
When one of the computers fails, the workload is picked up by other workstations. Data are also distributed at multiple sites.
9. Processor independence.
The end user is able to access any available copy of the data, and an end user's request is processed by any processor at the data location.
Disadvantages of DDBMS:
1. Complexity of management and control.
Applications must recognize data location, and they must be able to stitch together data from various sites. Database administrators must have the ability to coordinate database activities to prevent database degradation due to data anomalies.
2. Technological difficulty.
Data integrity, transaction management, concurrency control, security, backup, recovery, query optimization, access path selection, and so on, must all be addressed and resolved.
3. Security.
The probability of security lapses increases when data are located at multiple sites. The responsibility of data management will be shared by different people at several sites.
4. Lack of standards.
There are no standard communication protocols at the database level. For example, different database vendors employ different—and often incompatible—techniques to manage the distribution of data and processing in a DDBMS environment.
5. Increased storage and infrastructure requirements.
Multiple copies of data are required at different sites, thus requiring additional disk storage space.
6. Increased training cost.
Training costs are generally higher in a distributed model than they would be in a centralized model, sometimes even to the extent of offsetting operational and hardware savings. Distributed databases require duplicated infrastructure (physical location, environment, personnel, software, licensing, etc.) to operate
Jonathan Gunawan 1701297684 bb02
ReplyDelete25.
ASP:
1. Asp stands for Active Server Pages
2. ASP is released by Microsoft
3. ASP uses visual basic language
4. ASP application can be connected to MS SQL and MS Access database
5. Microsoft IIS Server supports ASP on windows
6. ASP is not a free language because ASP relies on windows and IIS that both of them are not free
7. ASP code can be interpreted
JSP:
1. JSP stands for java server pages
2. JSP I s released by SUN microsystems
3. JSP is java based language
4. JSP can be connected to any database by loading the appropriate driver
5. JSP supported by apache tomcat web server and linux based server support the website built using JSP
6. JSP is available for free
7. JSP code can be interpreted also compiled
Specialization
ReplyDelete- Process of defining a set of subclasses of an entity type
- Defined on the basis of some distinguishing characteristic of the entities in the superclass
- Classify a class of objects into more specialized subclasses
Subclass can define:
-Specific attributes
-Specific relationship types
Certain attributes may apply to some but not all entities of the superclass.
Some relationship types may be participated in only by members of the subclass.
Generalization
Reverse process of abstraction
Generalize into a single superclass
-> Original entity types are special subclasses
Generalization
-> Process of defining a generalized entity type from the given entity types
-> Generalize several classes into a higher-level abstract class
-> Includes the objects in all these classes
Constraints and Characteristics of Specialization and Generalization Hierarchies:
- Constraints that apply to a single specialization or a single generalization
- Differences between specialization/generalization lattices and hierarchies
Constraints on Specialization and Generalization
May be several or one subclass
Determine entity subtype:
- Predicate-defined (or condition-defined) subclasses
- Attribute-defined specialization
- User-defined
Two basic constraints can apply to a specialization/generalization:
- Disjointness Constraint
- Completeness Constraint
A. Disjointness constraint:
-> Specifies that the subclasses of the specialization must be disjoint: an entity can be a member
of at most one of the subclasses of the specialization
- Specified by d in EER diagram
If not disjoint, specialization is overlapping:
-> that is the same entity may be a member of more than one subclass of the specialization
- Specified by o in EER diagram
B. Completeness (or totalness) constraint
-> May be total or partial
-> Total specifies that every entity in the superclass must be a member of some subclass in the specialization/generalization (Shown in EER diagrams by a double line)
-> Partial allows an entity not to belong to any of the subclasses (Shown in EER diagrams by a single line)
-> In general, a superclass that was identified through the generalization process usually total, because the superclass is derived from the subclasses and hence contains only the entities that are in the subclass
Disjointness and completeness constraints are independent
have four types of specialization/generalization:
- Disjoint, total
- Disjoint, partial
- Overlapping, total
- Overlapping, partial