Why we need the database design
Database design is the method of generating a complete data model of the database.
This logical data model have all the required logical and physical design options and physical
storage constraints required to create a design in a Data Definition Language, which preserve
then be used to generate a database. Completely recognized data models have complete
attributes for every unit. It makes work as easier.
Various kinds of Database design:
1) Conceptual schema:
Formerly a database designer is responsive of the records which are to be laid
surrounded by the database; the designers must then decide where addiction is inside the
record. At times while records are distorted you can be shifting other records that are not
observable. For an exemplar, in a list of names and ages, presumptuous a state where multiple
populace can have the same age, but one being cannot have more than one age; the name is
reliant ahead the age, since if the age is dissimilar, then the related name is diverse too.
Though, the further manner about is dissimilar. One element can modify and not any more.
2) Logically structuring record:
On one instance the associations and reliance between the different bits of record
include gritty; it is probable to organize the records keen on a logical structure which be able to
follow by planed keen on the storage substance sustained with the database management
system. In the case of relational databases the storage substance are tables which lay up the
records in rows and columns.
Each table can be a completion of any a logical object or a bond combination among one
or more instances of one or more logical objects. Relations among tables could be laid up as
relations between child tables with parent tables. While multifaceted logical relationships are
themselves tables they will perhaps contain relations to more than one parent table.
In an Object database the storage objects communicate openly to the objects through
the Object-oriented programming language used to inscribe the projects that will handle and
process the record. The relationships can be defined as an element of the entity classes
concerned or as techniques that control on the object classes.
3) Physical design:
The physical design of the database indicates the physical design of the database on the
storage intermediate layer. These contain complete requirement of data elements, data
types, indexing options and other constraints exist in the DBMS data dictionary. It is the
complete design of a structure that contains units and the database's hardware & software
specifications of the system.
Pros of Database design:
1) Condensed data redundancy
In database design, different records are included and every logical data item is layup at
central place. This abolishes duplicating the data item in diverse records, and makes sure
constancy and keeps the storage space. The redundancy in the database systems cannot be
eradicated fully as present can be several presentation and technical reasons for contain some
quantity of redundancy. Though, the DBMS should be able to devious this redundancy in order
to avoid record variation.
2) Upgraded data security
While the record is stored substantively, impose security controls is greatly easier. The
DBMS guarantee to the only resources of approach to the database is during an official conduit.
So, data security verifies can be approved out at any time approach is attempt to receptive
record. To ensure the data base security, a DBMS offers security tools such as user codes and
passwords. Different verifies can be recognized for each type of approach like addition,
modification, deletion, etc. to each part of fact in the database.
3) Enriched data approach to users during use of host and query languages
In order to gather the requests of different users having diverse technical familiarity,
DBMS gives various types of interfaces such as query languages, application program interfaces,
and graphical user interfaces (GUI) that contain forms-style and menu-driven interfaces. A
form-style interface shows a form to each and every user and user interacts using these forms.
In menu-driven interface, the user interaction is during lists of selections known as menus.
4) Objectivity from applications programs
The application programmer wants to build up the application programs depending on
whether the users desires. The other concerns like simultaneous approach, security, data
integrity, etc., are griped by the DBMS itself. This makes the application development an easier