In the information environment there are objects and objects that require the storage of information about themselves. Therefore, we began to use data models, which, in addition to the main function, allow us to work with connections. This is necessary when creating any database. The organization itself can be physical or logical. In the first case, storage is provided at the machine level. Well and at the logical organization there is a direct interaction with the user, where certain software tools exert their influence. Today, the most basic data models are distinguished: hierarchical, relational and network.
With a hierarchical data model, the entire set of elements has links formed according to specific rules. Objects can be represented as an inverted tree that contains nodes on one level or another that have connections to each other. A node is a set of attributes that describe an object. The hierarchical tree has only one vertex, lying on the first level. Such a model is not devoid of significant shortcomings, manifested in the ineffectiveness of certain types of relations, as well as slow access to the lower levels of the hierarchical system.
Another thing is when using the relational data model, which is characterized by a very simple structure. It is implemented in the form of two-dimensional tables that support certain relationships. The relational approach for a long period of time was left without due attention, as it required the presence of serious machine resources. However, with the advent of personal computers, the situation has changed dramatically. And these models of data organization have virtually supplanted the rest of the system. The creator, when implementing this idea, provided the world with a tool for successful work with relations.
In a networked data model, any element can have a direct link to another element. There is some resemblance to a hierarchical system, but the difference is that multiple links with segments located at the senior level are allowed. In this case, it is not possible to trace the direction of links so clearly, therefore, they should be indicated in the description of the database. The disadvantages of this model include the inadequate preservation of information, but this problem is being solved very actively now.
Any databases are created based on the models listed. Differences between them are gradually erased due to the introduction of object-oriented information technology. Each model has special characteristics that allow you to achieve maximum effect with specific applications. The difference between relational databases and other analogs is that they are able to change the structure even after data entry. However, large databases that have an unchanged structure and constant interaction with applications can be most effective in terms of access speed.