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=====Network model=====
{{Main|Network model (database)}} ''RANA''
In this model a hierarchical relationship between two record types (representing real-world entities) is established via the ''set'' construct. A set consists of circular [[linked list]]s where one record type, the set owner or parent, appears once in each circle, and a second record type, the subordinate or child, may appear multiple times in each circle. In this way a hierarchy may be established between any two record types, e.g., type A is the owner of B. At the same time another set may be defined where B is the owner of A. Thus all the sets comprise a general [[directed graph]] (ownership defines a direction), or ''network'' construct. Access to records is either sequential (usually in each record type) or by navigation in the circular linked lists.
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