Types of Database Network Model
Database Network Model:
How DataBase Network Model Works? This tutorial educates you hat how the database network model works. It controls the logical construction of a database and fundamentally determines in which way data can be stored, prearranged, and manipulated.
There are four public types of database models that are useful for different types of data or info. Contingent upon your exact needs, one of these models can be rummage-sale
1. Hierarchical databases.
2. Network databases.
3. Relational databases.
4. Object-oriented databases.
1. Hierarchical Database Model:-
It is one of the oldest database models developed by IBM for Information Management System. In a hierarchical database model, the data is rearranged into a tree-like structure. In modest language, we can say that it is a set of ordered data in a tree structure.
This type of Database model is seldom used currently. Its building is like a tree with nodes on behalf of records and branches on behalf of fields.
The windows archive used in Windows is a sample of a hierarchical database. Shape settings are stored as tree constructions with nodes.
The following figure shows the generalized construction of a Hierarchical database model in which data is stowed in the form of a tree-like structure (data represented or stored in the root node, parent node, and child node).
The following figure displays the example of a hierarchical database model for the college management system. This type of database employs the “parent-child” relationship of storage data.
• The model allows us easy adding and deletion of new info.
• Data at the top of the Hierarchy is very fast to admission.
• It worked well with lined data storage mediums such as adhesive tape.
• It tells well to anything that works through one-to-many relationships. For example; there is a leader with many managers below them, and those managers have many staffs below them, but each employee has only one boss.
• It needs data to be repeatedly stored in many different objects.
• Now a day there is no longer use of linear data storage mediums such as tapes.
• Searching for data requires the DBMS to run through the whole model from top to lowest until the required information is found, creation queries very slow.
• This model provision only one to many relationships, many to many relationships are not reinforced.Network databases
2. Network database Model
The network database Model is a type of database model wherein multiple associate records or files can be linked to multiple landlord files and vice versa.
The model can be viewed as an upside-down tree where each associate information is the branch linked to the proprietor, which is the bottom of the tree. Essentially, relationships are in a net-like form where a single element can point to multiple data rudiments and can itself be piercing to by manifold data rudiments.
• The network model is theoretically simple and easy to project.
• The network model can represent redundancy in data more effectively than in the hierarchical model.
• The network model can switch the one to many and many to many relationships which is a real help in modeling the real-life circumstances.
• The data access is easier and supple than the hierarchical model.
• The network model is better than the hierarchical model in dividing the plans from the complex physical storage facts.
• All the records are maintained using pointers and hence the whole database building becomes very complex.
• The insertion, deletion and updating operations of any record require a large number of pointers adjustments.
• The structural changes to the database is very difficult.
3.Relational Database Model
A relation is nothing but a table of standards. Every row in the table signifies a group of related data values. These rows in the table mean a real-world entity or connotation.
The table name and column names are helpful to interpret the sense of values in each row.
The data are meant as a set of relations. In the relational model, data are stored as tables. However, the physical storage of the data is self-governing of the way the data are logically organized.
The terminology used in Relational Model
• Tuple: Each row in a table is acknowledged as a tuple.
• Cardinality of a relation: The number of tuples in a relative determines its cardinality. In this case, the relation has a cardinality of 4.
• Degree of a relation: Each column in the tuple is called an attribute. The number of attributes in a relation panels its degree.
Keys of a relation-
• Primary key- it is the key that uniquely identifies a table. It doesn’t have null values.
• Foreign key- it mentions to the primary key of some other table.it permits only person values which seem in the primary key of the table to which it refers.
Some of the examples of relational databases are as follows.
- Oracle: Oracle Database is usually referred to as Oracle RDBMS or simply as Oracle. It is a multi-model database management scheme shaped and marketed by Oracle Corporation.
- MySQL: MySQL is an open-source relational database management system (RDBMS) founded on Structured Query Language (SQL). MySQL innings on almost all platforms, counting Linux, UNIX, and Windows.
- Microsoft SQL Server: Microsoft SQL Server is an RDBMS that ropes a wide variety of transaction processing, business intelligence, and analytics applications in corporate IT environments.
- PostgreSQL: PostgreSQL, often simply Postgres, is an object-relational database management system (ORDBMS) with an emphasis on extensibility and values compliance.
- DB2: DB2 is an RDBMS intended to store, analyze, and retrieve data efficiently.
• Relational model is one of the greatest over-all used database model.
• In relational model, vicissitudes in the database structure do not touch the data access.
• The revision of any info as tables containing of rows and columns is much easier to understand.
• The relational database manacles both data individuality and structure independence concept which makes the database design, maintenance, administration and practice much calmer than the other models.
• In this we can write multifaceted query to accesses or modify the data from database.
• It is easier to uphold security as compare to other models.
• Mapping of substances in relational database is very problematic.
• Object oriented paradigm is missing in relation model.
• Data Integrity is problematic to ensure with Relational database.
• Relational Model is not appropriate for huge database but appropriate for small database.
• Hardware expenses are incurred which make it expensive.
• Ease of design can lead to good design.
• Relational database system hides the implementation difficulties and the physical data storage details from the users.
4. Object-oriented databases Model
object-oriented databases (OODB) are databases that signify data in the form of substances and classes. In object-oriented terminology, an object is a real-world object, and a class is a collection of objects.
Object-oriented databases follow the fundamental values of object-oriented programming (OOP). The combination of interpersonal model topographies (concurrency, transaction, and recovery) with object-oriented values results in an object-oriented database model.
• Object database can handle dissimilar types of data while relational database handles a single data. Unlike traditional databases like hierarchical, network, or relational, object-oriented databases can handle dissimilar types of data, for example, pictures, voice video, including text, numbers, and so on.
• Object-oriented databases provide us code reusability, real-world modeling, and improved reliability and flexibility.
• The object-oriented database is having low maintenance costs as compared to another model because most of the tasks within the system are encapsulated, they may be reused and incorporated into new tasks.
Entity-relationship Data Base model
This model imprisonment the relationships among real-world entities much like the network model, but it isn’t as straight tied to the physical construction of the database. Instead, it’s often used for scheming a database conceptually.