Search results
Results from the WOW.Com Content Network
An entity–relationship model (or ER model) describes interrelated things of interest in a specific domain of knowledge. A basic ER model is composed of entity types (which classify the things of interest) and specifies relationships that can exist between entities (instances of those entity types).
Since airline reservation systems are business critical applications, and they are functionally quite complex, the operation of an in-house airline reservation system is relatively expensive. Prior to deregulation [clarification needed], airlines owned their own reservation systems with travel agents subscribing to them. Today, the GDS are run ...
The MARS-1 train ticket reservation system was designed and planned in the 1950s by the Japanese National Railways' R&D Institute, now the Railway Technical Research Institute, with the system eventually being produced by Hitachi in 1958. [6] It was the world's first seat reservation system for trains. [7]
A sample entity–relationship diagram. One of the most common types of conceptual schemas is the ER (entity–relationship model) diagrams. Attributes in ER diagrams are usually modeled as an oval with the name of the attribute, linked to the entity or relationship that contains the attribute.
The enhanced entity–relationship (EER) model (or extended entity–relationship model) in computer science is a high-level or conceptual data model incorporating extensions to the original entity–relationship (ER) model, used in the design of databases.
An entity–relationship model (ERM) is an abstract conceptual representation of structured data. Entity–relationship modeling is a relational schema database modeling method, used in software engineering to produce a type of conceptual data model (or semantic data model ) of a system, often a relational database , and its requirements in a ...
Get AOL Mail for FREE! Manage your email like never before with travel, photo & document views. Personalize your inbox with themes & tabs. You've Got Mail!
The departure control system (DCS) is the system used by airlines and airports to check-in a passenger. The DCS is connected to the reservation system enabling it to check who has a valid reservation on a flight. The DCS is used to enter information required by customs or border security agencies and to issue the boarding document.