Chapter 7, Problem 7.1RQ

Program Plan Intro

Definitions of the following terms:

a. Application partitioning

b. Application programming interface

c. Client/server system

d. Middleware

e. Three-tier architecture

f. locking

g. versioning

h. deadlock

Explanation of Solution

Application partitioning

The method of assigning components of application software, after it is written, to client or server partitions in order to gain increased performance and interoperability is termed as application partitioning. Here, interoperability refers to ability to function on different platforms.

Application programming interface (API)

An API is a set of routines, protocols and tools that are used by an application program to interact with other software applications. APIs are used for software development and in context to database APIs are used to connect an application software with the database to access or manipulate data in the database.

Client/server system

It is a networked computing model in which processes are distributed between clients and servers, which provide the needed services. Generally heavy processing applications are stored on the server and light application reside on a client. Client continuously interacts with the server to perform certain tasks. In context of a database system, the database along with the DBMS generally resides on a server and server is responsible for processing the DBMS. End user application system resides on the client which requests services from the client.

Middleware

Middlewares are softwares which act as a bridge between application and operating system or between two different applications. They facilitate users working on one application to interact with other software without understanding and coding the low-level routines required to achieve interoperability.

Three-tier architecture

It is a three-layer client/server configuration where one client layer and two server layers are present. This architecture contains one additional server layer as compared to two-tier client/server architecture.

Locking

It is a mechanism for making the data exclusive to one user during an update operation and making it unavailable to other users, until the update is completed or aborted.

Versioning

It is an approach for concurrency control during which each transaction under execution is limited to a portion of the database during its execution period, and when a transaction tries to modify a record, new record version for it is created instead of overwriting the old record.

Deadlock

It is a situation in which no progress can be made during transaction processing. It occurs when two or more transactions have acquired some common limited resources.