Unified Database Language (UDL) is language that supports all three of the well known approaches – relations, hierarchies, networks in a uniform and consistent manner. It is not a self-contained language, rather it is explicitly intended as “tightly coupled” set of database extensions to existing programming languages such as COBOL, PL/I. Mostly PL/I is used for implementation.
It is independent on any one specific host programming language, it can be incorporated into a variety of programming languages with suitable syntactic modifications. In addition to supporting all three approaches UDL also provides both record-at-a-time and set-at-a time operations for each of them as shall we see.
- The set level is desirable for reasons of productivity and ease of programming.
- The record level serves as bridge to existing function in the host language.
Classification :
Unified Database Language :
- Information System
- Data management System
- Database Design and Models
- Query languages
- Theory of Computation
- Theory and algorithms for computer domains
- Database Theory
- Database Query languages (Principles)
Advantages :
- Self-contained language.
- Use of existing programming languages.
- Independent of a host programming language.
- Easy to use and flexible.
- The Software Architecture Must Be Communicated Effectively.
Disadvantages :
- Use of limited languages.
- Formal Notation is Not Necessary
- Less information is available on different domains of UDL as research is going on.
- Ascending Degree of Complexity.