Introduction of Unified Database Language (UDL)

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 : 

1. Information System
2. Data management System
3. Database Design and Models
4. Query languages
5. Theory of Computation
6. Theory and algorithms for computer domains
7. Database Theory
8. 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.