9. The Client/Server Database Environment

Chapter 9 and Chapter 10

MODERN DATABASE MANAGEMENT

10.The Internet Database Environment

Tugas MK Sistem Basis Data

Nama : Dody Iskandar NIM : 59719 Minat : SKI

9. The Client/Server Database Environment

9. Describe six categories of middleware.

Answer :

Middleware : software that allows an application to inter-operate with other software without requiring the user to understand and code the low-level operations necessary to achieve interoperability.

Chapter 9

Review Questions (halaman 357)

Six categories of middleware :1. Asynchronous RPC (remote procedure calls).

The client requests services, but does not wait for a response. It will typically establish a point-to-point connection with the server and perform other processing while it waits for the response. If the connection is lost, the client must re-establish the connection and send the request again. This type of middleware has high scalability but low recoverability.

Chapter 9

Six categories of middleware :2. Synchronous RPC (remote procedure calls).

A distributed program using syncronous RPC may call sevices available on different computers. This middleware makes it possible to establish this facility without undertaking the detailed coding usually necessary to write an RPC.

Chapter 9

Six categories of middleware :3. Publish / subcribe

This type of middleware monitors activity and pushes information to subscribers. It is asynchronous – the clients, or subscribers, perform other activities between notifications from the server. The subscribers notify the publisher of information that they wish to receive and when an event occurs which contains such information, it is sent to the subscriber, who can then elect to receive the information or not.

Chapter 9

Six categories of middleware :4. Message-oriented middleware (MOM).

MOM is also asynchronous software, sending messages that are collected and stored until they are acted upon, while the client continues with other processing. Workflow applications such as insurance policy application, which often involve several processing steps, can benefit from MOM. The queue where the requests are stored can be journalized, thus providing some recoverability.

Chapter 9

Six categories of middleware :5. Object request brokers (ORBs).

This type of middleware makes it possible for applications to send objects and request services in an object-oriented system. The ORB tracks the location of each object and routes requests to each object. Current ORBs are synchronous, but asynchronous ORBs are being developed.

Chapter 9

Six categories of middleware :6. SQL – oriented data accessConnecting applications to databases over

networks is achieved by using SQL – oriented data access middleware. This middleware also has the capability to translate generic SQL into the SQL specific to the database. Database vendors and companies that have developed multidatabase access middleware dominate this middleware segment.

Chapter 9

10. The Internet Database Environment

4. Explain why attaching a database to a Web page is important in the facilitation of e-business.

Answer :

Electronic business (e-business) : a technology-enable business that is using Internet-related technology to facilitate the development of more integrated relationships with customers and suppliers.

Chapter 10

Review Questions (halaman 389)

10. The Internet Database EnvironmentThe servers store information in database to

be sent to the browsers on request. It is necessary to access databases for current information, such as inventory availability, and to record information, such as the data items associated with an order, in these applications.

Chapter 10

Other sites provide more interactivity between the user and the database, in that the user can send back information to a database that is attached to a site. This capability has supported the explosive growth of e-business, as orders may be placed on-line by customers. The customer is frequently able to determine prior to placing an order whether a desired product is in stock or not, and how long it should take to receive it. Applications that enable e-business include the capability to both display and load databases attached to a site.

Chapter 10