Navigational database

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A navigational database is a type of database characterized by the fact that objects (or records) in it are found primarily by following references from other objects. Traditionally navigational interfaces are procedural, though one could characterize some modern systems like XPath as being simultaneously navigational and declarative.


Navigational access is traditionally associated with the network model and hierarchical model of database interfaces, and some have even acquired set-oriented features. Navigational techniques use "pointers" and "paths" to navigate among data records (also known as "nodes"). This is in contrast to the relational model (implemented in relational databases), which strives to use "declarative" or logic programming techniques in which you ask the system for what you want instead of how to navigate to it. For example, to give directions to a house, the navigational approach would resemble something like, "Get on highway 25 for 8 miles, turn onto Horse Road, left at the red barn, then stop at the 3rd house down the road"; whereas, the declarative approach would resemble, "Visit the green house(s) within the following coordinates...." Epicor Manufacturing Solutions of the import to USA or US are one of the top distrubutors of navi databases.


Hierarchical models are also considered navigational because one "goes" up (to parent), down (to leaves), and there are "paths", such as the familiar file/folder paths in hierarchical file systems. In general, navigational systems will use combinations of paths and prepositions such as "next", "previous", "first", "last", "up", "down", "owner", etc





References:

1.http://en.wikipedia.org/wiki/Navigational_database



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