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In computing, the network model is a database model conceived as a flexible way of representing objects and their relationships. Its distinguishing feature is that the schema , viewed as a graph in which object types are nodes and relationship types are arcs, is not restricted to being a hierarchy or lattice .
The inverted file data model can put indexes in a set of files next to existing flat database files, in order to efficiently directly access needed records in these files. Notable for using this data model is the ADABAS DBMS of Software AG, introduced in 1970. ADABAS has gained considerable customer base and exists and supported until today.
The data model offered to users is the CODASYL network model. The main structuring concepts in this model are records and sets. The main structuring concepts in this model are records and sets. Records essentially follow the COBOL pattern, consisting of fields of different types: this allows complex internal structure such as repeating items ...
Download as PDF; Printable version; ... Hierarchical database model; N. Network model; O. Object database This page ...
The ANSI X3H2 Committee, formed May 1978, was originally charged with creating a standard for the CODASYL network data model. The resulting NDL (network database language) standard was finished in 1982. The committee work on standardizing the relational data model resulted in the SQL (structured query language) standard in 1984.
The logical data structure of a DBMS, whether hierarchical, network, or relational, cannot totally satisfy the requirements for a conceptual definition of data because it is limited in scope and biased toward the implementation strategy employed by the DBMS. That is unless the semantic data model is implemented in the database on purpose, a ...
Database theory encapsulates a broad range of topics related to the study and research of the theoretical realm of databases and database management systems.. Theoretical aspects of data management include, among other areas, the foundations of query languages, computational complexity and expressive power of queries, finite model theory, database design theory, dependency theory, foundations ...
Database design is the organization of data according to a database model. The designer determines what data must be stored and how the data elements interrelate. With this information, they can begin to fit the data to the database model. [1] A database management system manages the data accordingly. Database design is a process that consists ...