Simple tables of information can be described by Prolog structures, and relationships between tables can be described by Prolog rules. The retrieval process is inherent in the resolution operation. Prolog can replace the DDL, DML, and Query Language which are usually embedded in an imperative language. Deductive capability is an advantage but logical inferences take longer than ordinary table look-up methods. Expert Systems Expert systems consists of a database of facts, an inferencing process, some heuristics about the domain, and some friendly human interface.
Logic programming can help deal with the problem of incompleteness of the database.
Prolog is missing the ability to query the user for additional information when it is needed. Natural Language Processing e.g., Intelligent databases. Intelligent knowledge-based systems. Forms of logic programming have been found to be equivalent to context-free grammars. Some kinds of semantics of natural languages can be made clear by modeling the languages with logic programming.