计算机专业英语期末论文翻译

Database Application Testing

1.Introduction

Databases play a pivotal role in almost every organization in today’s information-based society. Commercial Database management

systems(DBMSs) provide organizations with efficient access to huge amounts of data without affecting the integrity of data and relieving the user of the any need to understand the low-level implementation details. Over the years tremendous efforts have been devoted to ensuring use of efficient and integrity protecting data structures and algorithms by DBMSs. However, little has been done to develop systematic techniques for ensuring correctness of applications using these DBMSs. Many testing techniques have been developed to help ensure that behaviour of a program is in accordance with the specifications. However, these techniques mostly target programs written in traditional imperative languages and can’t be of much help when it comes to database applications. Like any other program, database application program can be viewed as an attempt to implement a function. Considered this way, both the input and output spaces of this function will include database state apart from the explicit input and output parameters of the application. This affects substantially the way a test case is defined, generated and executed to check correctness of application. Hence there is a need for new approaches specifically oriented towards testing database applications.

Testing database application programs involves the following phases :

•Extraction of information from database schema

•Generation of test data and Populating test database

•Generation of test cases as input to the application program

•Validation of database state and output after execution

Using live data has several limitations. It may not reflect sufficiently wide variety of possible situations and even if it does, it might be difficult to find them in a large database. Secondly, privacy or security constraints might prevent the user from seeing sensitive data. Hence, various methods for generating synthetic test data have been proposed. When generating data and populating the test database, its important to generate valid and interesting data e.g. it would be advisable to select data so as to include situations which the tester believes are likely to occur or will expose faults in application. The technique used for test data generation will determine the extent of coverage of test database. Selecting a good initial database state so as to include a wide variety of scenarios resembling real data for the particular application is very beneficial. Since database state plays an important role in determining the