SQL RDBMS Concept – Features & Advantages

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1. Concept Of SQL RDBMS

Today, in this RDBMS tutorial, we will discuss SQL RDBMS Concept. Firstly, we will see what is RDBMS and the forms of SQL RDBMS. Moreover, we will see SQL Constraints, RDBMS examples, and SQL RDBMS normalization. Also, we will discuss SQL RDBMS features and advantages. In this SQL RDBMS tutorial, we are going to learn about the basic concepts of RDBMS in SQL which will help us study and work well with the technology.
So, let’s start the SQL RDBMS Concept.


SQL RDBMS Concept – Features & Advantages

2. What is RDBMS?

Relational Database Management System is a type of Database management i.e. DBMS which focuses on the relational model. A relational database allows us to deal with different types of data in different ways. The data can retrieve and organize in many different ways with the advantage that the data won’t alter in the database. Data can access using an API called SQL.
Do you know about SQL RDBMS Database System

3. SQL RDBMS Concept

Follow are the forms of SQL RDBMS Database:

a. Tables

The data that gets stored in databases objects are stored in Tables. It is the simplest form of storing data.
A Table has rows and columns used to store the entities.

b. Field

Every table is shifting into smaller entities known as fields. The fields within the CUSTOMERS table incorporates ID, NAME, AGE, ADDRESS, and earnings.
A field could be a column in a very table that’s designed to take care of specific info concerning each record within the table.

c. Record or a Row

A record is additionally known as a row of data is every individual entry that exists in a very table. as an instance, there are seven records within the on top of CUSTOMERS table. The following could be a single row of information or record within the CUSTOMERS table −
A record could be a horizontal entity in a very table.

d. Column

A column could be a vertical entity in a very table that contains all info related to a particular field in a very table.
For example, a column within the CUSTOMERS table is ADDRESS, that represents location description and would be as shown below −

e. NULL value

A NULL price in a very table could be a price in a very field that seems to be blank, which implies a field with a NULL price could be a field with no price.
It is vital to know that a NULL price is totally different than a zero price or a field that contains areas. A field with a NULL price is that the one that has been left blank throughout a record creation.

4. SQL Constraints

Constraints in SQL are the principles implemented on information columns on a table. These are wont to limit the sort of information which will move into a table. This ensures the accuracy and reliability of the data within the database.
Have a look at SQL Operators
Constraints will either be column level or table level. Column level constraints are applied solely to at least one column whereas, table level constraints are applied to the whole table.
Following are a number of the foremost commonly used constraints accessible in SQL −

SQL Constraints

SQL Constraints

  • NOT NULL Constraint − Ensures that a column cannot have a NULL price.
  • DEFAULT Constraint − Provides a default value for a column once none is specified.
  • UNIQUE Constraint − Ensures that everyone the values in a very column square measure totally different.
  • PRIMARY Key − Uniquely identifies every row/record in a very database table.
  • FOREIGN Key – It uniquely identifies a row/record in any another database table.
  • CHECK Constraint − The CHECK constraint ensures that everyone values in a very column satisfy bound conditions.
  • INDEX − Wont to produce and retrieve data from the info terribly quickly.

5. SQL RDBMS – Database Normalization

Database normalization is that the method of with efficiency organizing data in a very database. There square measure 2 reasons for this normalization method −

  • Eliminating redundant information, as an instance, storing the same data in additional than one table.
  • Ensuring data dependencies add up.

Both of these reasons are worthy goals as they cut back the number of space a database consumes and ensures that information is logically held on. Normalization consists of a series of guidelines that facilitate guide you in making an honest database structure.
Normalization guidelines are divided into traditional types; think about a form because the format or the approach an info structure is ordered out. The aim of normal forms is to prepare the database structure, in order that it complies with the principles of 1st normal form, then second normal form and eventually the third normal form.
It is your option to take it more and go to the fourth normal form, fifth traditional type and so on, generally, the third normal form is quite enough.

  • First normal form (1NF)
  • Second normal form (2NF)
  • Third normal form (3NF)

6. Basic Features of SQL RDBMS

Below, discussed are the basic SQL RDBMS Features:

  • Offers info to save within the tables.
  • Various users will access it along that manages by one user.
  • Virtual tables offer for storing the perceptive information.
  • So as to solely determine the rows, we use the first key.
  • We continuously save the information continuously in rows and columns.
  • To retrieve the information, we use indexes.

7. SQL RDBMS Ideas

Relation within the SQL RDBMS is that the deposit of tuples having the similar characteristics. A relation in RDBMS means that the set of the entities and data contained in them. The entities are completely different instances and their relation organizes in several rows and columns within the data table. The connected info is of identical domains and constraints. By deleting previous data and by inserting new knowledge, relations are altered within the database model.

RDBMS Concept


a. Domain in RDBMS

The domain describes probable terms collected jointly that invariably have identical characteristics and additional constraints. A domain will be concerned in an exceedingly feature however provided that the feature could be an issue of a specific set.

b. RDBMS info

The association between completely different databases is termed because of the electronic information service. Here all the info is connected in terms of the tables they’re held on in. The users are able to access them. RDBMS info is completely different from that of database management system.
The RDBMS speaks concerning relations concerning completely different entities gift within the info. Traditional info assists solely the tables whereas RDBS at the side of the tables tells their connections too. Traditional databases provide consisted strategies however databases of RDBMS don’t provide any methodologies however instead offers connections that connect one single object with another.
The hold on the database is termed as executable codes. The info collects and saves data in which specific procedure term because of the stored procedure. throughout this, the codes stored that is used for encapsulation, delete, etc. The programmers are able to add extensions of the syntaxes of SQL due to the applications of the Apis within the hold on processes.

c. Constraints

Constraints are a variety of limitations functional to the database. They create out there the thanks to using the trade logic and also the laws within the info. within the database, it will be applied within the sort of make sure limits that verify for the set of laws that the developer has incomprehensible. Constraint additionally for limiting the facts that may be saved within the relations. they’re applied to verify the province performance and to stay it protected.
The main principles of the RDBMS Model are:

  • Entity integrity: The entity integrity says that in an exceedingly info, all the data ought to be organized having a single key. The distinctiveness of all the data is maintained by this principle.
  • Referential integrity: In this, we keep all the values true in the database for foreign keys.

d. RDBMS Operators

There are many relational operators that perform on the RDBMS. They are:

  1. Union operator mingles the rows of two relations and ignores the replacement. It additionally takes the traced ones from the output.
  2. Intersection operator offers a collection of rows that are identical to 2 relations.
  3. Difference operator offers the result by having a pair of relations and offers the distinction of rows from 1st that doesn’t exist in second.
  4. The product completes on 2 relations. It works as a cross join operator.

e. Primary and Foreign Keys

  • Primary key: The primary key finds out the similarity within the relationship. For the whole table, there’s only 1 primary key. Each table possesses a specific primary key that cannot share by other tables.
  • Foreign key: The foreign key is a key used for a different table of data that refer to the first key. There are several foreign keys for one table. It depends on the first key and its call thus on refer those foreign keys to the table. Each foreign key will share and it speaks concerning the coordination among the data of various tables.

f. Index in RDBMS

We use the indexes for quicker accessing of the info and their structure. Combining all the characteristics it makes it potential to search out (the data-the info-the information) quicker and additionally permits the similar data to find terribly well.

g. RDBMS normalization

Normalization could be a very important a part of a relational model. Normal forms are the overall sort of normalization. It helps in dropping severance to spice up the entire knowledge. It’s varied drawbacks because it boosts the issue and features a varied operating cost of giving out. It’s a group of processes that remove the realm that’s non-atomic and severance {of information-of knowledge-of knowledge} that saves data management and thrashing of data irresponsibleness.
There are nine normalizations in SQL RDBMS database, that use within the database. These are as follows:

  • 1st normal form: This table represents a relation of distinctive teams.
  • Second normal form: It isn’t much charge on the division of any contender key.
  • Third normal form: Each non- prime feature is a non-transitively charge on each contender key
  • Elementary key normal form: This key dependency modifies the sensible dependency in an exceeding table.
  • Boyce Codd traditional form: “All non-trivial functional reliability relies on superkey”.
  • Fourth normal form: “All non-trivial multivalent reliability could be dependent on a superkey”.
  • Fifth normal kind (5NF): “Every non-trivial be part of dependency is applied by the super key.
  • Domain/key normal kind (DKNF): “All restriction are logical outcomes of the domain limitations.
  • Sixth normal kind (6NF): No non-trivial be part of reliabilities at all”.

h. Data Abstraction

There are three stages of data generalization in SQL RDBMS. and that they are:

  1. Physical level: It is that the least potential stage that explains. However, info holds on within the database.
  2. Logical level: It is that the next senior stage within the ladder that offers the generalization. It tells what info hold on and additionally tells the connection between them.
  3. View level: It is that the uppermost stage within the ladder that explains a part of the complete info. It permits the consumer to look at the database and do the inquiry.

i. RDBMS Extensions and Intensions

Extension: Extension describes the number of tuples existing in an exceedingly table at any time and it’s fully dependent on time.
Intension: Intension tells concerning the name, configuration, and limitations of the table and doesn’t rely on time.

j. Data Independence in RDBMS

The freedom of {the information-the knowledge-the knowledge} hold on within any application term as data independence. Now, for the storage configuration and permits amending the representation of the info hold on within the database. However, doesn’t able to modify the representations in the supreme stage.
There are 2 sorts of knowledge independence:

  1. Physical data independence: It permits the alteration to complete within the physical point and never goes to possess an impact on the logical half.
  2. Logical data independence: It permits the modification to complete at the logical half and additionally it affects the reading level.

k. View

For looking at the data, there’s a virtual table of rows and columns this virtual table term as a view. It save within the knowledge directory and displays the file. Since it’s a virtual table and has no physical existence, thus it’s regarding the logical level.

l. E-R Model

The full sort of this E-R model is that the entity relationship. this can be a sort of representing objects within the database and also the relationships between the various objects. within the sensible world additionally, it represents varied entities and also the relationship between those completely different entities


ACID stands for Atomicity, Consistency, Isolation, and durability and it performs an essential task within the database. The ACID options assist in dominant the accuracy within the data center. The ACID options create the database simple to use. It permits protected sharing of data among the tables. while not the ACID options, the info are in conflicting and additionally, it’ll become imprecise.

n. Cardinality

For arrangement and correct organizing of the information held on, we tend to use cardinality. This arrangement tool is used within the entity relationship diagrams representing relationships between completely different entities within the table. The cardinality is of various varieties and that they are :

  • One to one: This cardinality connects one single object with another single object.
  • One to many: This cardinality connects one single object with many single objects.
  • Many to many: This cardinality connects many single objects with many alternative single objects.
  • Many to one: This cardinality connects many objects with one single object

8. Advantages of RDBMS

  • Data just hold on once thus multiple documentation changes don’t seem to need.
  • Higher safety measures
  • The table arrangement is simple and easy for info users to understand and use.
  • RDBMSs allow various info users to admittance a info at the same time.
  • RDBMS comply with the database manager to limit admission to certified users, and gift rights to entity users depending on the sorts of database work they are doing
  • RDBMSs provide admission to the info via a server daemon, an ardent computer code program that responds to needs on a collection of connections and permits info users to attach and create use of the database.
  • SQL language supports it.

So, this was all in SQL RDBMS concept. Hope you like our explanation of the Relational Database Management System.

9. Conclusion – Relational Database Management System

Hence, in this SQL RDBMS Concept tutorial, we discussed the Relational Database Management System concept in SQL. Also, we saw features of RDBMS and main RDBMS ideas. Moreover, we discussed RDBMS advantages, forms of RDBMS and database normalization. Along with this, we also learned SQL constraints.
For reference

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