Scenario You have been asked to explore ree databas ernatives for a merchant who provides shoes to retail stores. The merchant needs the database to keep the financial records, employee records,...

Solution 1:
Following are three Database systems:
Hierarchical Databases -
Description: This database system is mainly used for mainframe applications and is in the
existence for a very long period. It is said to be one of the oldest way of storing and managing
data. Though it is a traditional one but still finds its existence in today’s applications.
Structure: Hierarchical databases are organized in the form of a pyramid i.e. na
ow at the top
and
oad at the bottom. In order to form higher-level records, similar or related records are
grouped together. And the lower level records sit above the subordinate records. In this structure,
parent record is placed at the pyramid’s top is known as root record. Parent records usually have
child records. A child record is linked to one and only one parent record, just like a usual family
tree. Parent record on other side can have many child records linked to it. This association gives
ise to a hierarchy. Such databases work in a top down manner (Types of Database Management
Systems).
Search: When a record is to be searched, the searching begins from top of the pyramid i.e. from
the parent record. Then it moves down the pyramid i.e. from topmost parent to bottom most child
until the desired record is retrieved. One point to be noted is that a record which is a child to
some other record, can also act as parent to some other record.
Analysis: The main benefit of the hierarchical database is that it can be accessed and updated
apidly. This is so because of its similarity to a tree and also the relationships existing between
the records are well defined well in advance. But the design of hierarchical database is very rigid.
When a record is to be inserted, this may even lead to redefining the whole database. Examples
of hierarchical databases include IMS (IBM).
Network databases - Network databases resemble the hierarchical respect to hierarchical
structure. Also, they are usually use on mainframe computers. But there are certain key points
which put it in a different category(Types of Database Management Systems).
Structure - Instead of an upside-down tree, a network database has a network of interconnected
ecords. In such databases, children are known as members and parents are known as owners.
The difference lies in the fact that each of the children or members can possess more than one
parent i.e. one owner. Relationships between the records are to be defined well in advance.
Analysis - Network databases have better flexibility than hierarchical databases. This is so
ecause of the presence of interconnectivity among the records, a new insertion can be done
easily without affecting the already existing database. But there is a restriction on the number of
connections which can exist between records.
Such network model is being adopted by many vendors like IDMS, Unisys, VAX-DBMS and
SUPRA.
Relational databases - In these databases, the relationships between data files are not
hierarchical. They are relational in nature. Instead of traversing the whole hierarchy to search a
ecord, which happens in hierarchical and network databases, relational databases establish the...