Database evolution

In this section, we will briefly discuss how databases have evolved over time.

Hierarchical database models

Hierarchical databases are a type of database management system (DBMS) that follows a hierarchical structure for organizing data. This structure is similar to a tree, with the root node at the top and child nodes branching out from it. Each child node can have multiple child nodes of its own, and so on, creating a hierarchical structure of data.

In this model, data is organized into records, which are stored in a hierarchy of parent-child relationships. Each record is linked to one or more child records, forming a tree-like structure. The parent record is called the owner record, and the child records are called member records. The owner record can have one or more member records, but each member record can only have one owner record.

One of the key features of hierarchical databases is the use of pointers or links to connect records. These links...