chaaru
2014-10-16 01:58:48 UTC
I am going to start writing on Computer topics, starting with, what
it's a tough topic to understand. Trust me, when I first read the
chapter, every thing sounded Greek and Latin* to me, so, I re-read it
couple of more times and I forgot what had been so difficult!
So, what is DBMS? It is Data Base Management System. Off course!
I'm sure all you know the full form, but have you really ever given a
thought to the words that make up the full form - 'cause that is where
the entire secret lies in understanding the core of this chapter!Data
- is any input which has been processed. It can be in numeric,
alphabetic or alphanumeric form. Try to imagine data as physical
files...the kind of dusty files found in government offices.
This processed data (or dusty files) needs to be stored and kept
somewhere, so that when we need them we can easily retrieve it.
But where do we keep it? How do we keep it?
Don't worry; the computer experts have solved your problem by
creating the 'database'.
Database - is simply a 'place' where all the data are collected and
stored in an organized manner.
Think of it as a collection of many steel racks, like the ones found
in old government offices! All the files/data are kept according to
their serial numbers/file/folder names (or any other identification
style), and stored in the racks/database.
Management system - In government officers, there are peons who are
responsible for keeping the files in the right place, bringing
required files to the senior officers, putting it back again after
updating the files etc., this is nothing but the system of file
management in the office.
Similarly, in computer's database, it's 'management system' is doing
most you (the non-engineering ones), consider as a difficult topic -
DBMS.
Only because it sounds so serious and technical doesn't actually meanDBMS.
it's a tough topic to understand. Trust me, when I first read the
chapter, every thing sounded Greek and Latin* to me, so, I re-read it
couple of more times and I forgot what had been so difficult!
So, what is DBMS? It is Data Base Management System. Off course!
I'm sure all you know the full form, but have you really ever given a
thought to the words that make up the full form - 'cause that is where
the entire secret lies in understanding the core of this chapter!Data
- is any input which has been processed. It can be in numeric,
alphabetic or alphanumeric form. Try to imagine data as physical
files...the kind of dusty files found in government offices.
This processed data (or dusty files) needs to be stored and kept
somewhere, so that when we need them we can easily retrieve it.
But where do we keep it? How do we keep it?
Don't worry; the computer experts have solved your problem by
creating the 'database'.
Database - is simply a 'place' where all the data are collected and
stored in an organized manner.
Think of it as a collection of many steel racks, like the ones found
in old government offices! All the files/data are kept according to
their serial numbers/file/folder names (or any other identification
style), and stored in the racks/database.
Management system - In government officers, there are peons who are
responsible for keeping the files in the right place, bringing
required files to the senior officers, putting it back again after
updating the files etc., this is nothing but the system of file
management in the office.
Similarly, in computer's database, it's 'management system' is doing
the work of the peon; bring the required files, putting back in the
right place, etc. but more efficiently than a peon and faster too!!
I really do hope some vapour-ish ideas are forming in your head about DBMS!
Thus, putting down all our ideas in definition form - DBMS is a software,
(i) which helps a user in creating a collection of records and
information and storing them on the computer in a systematic way
(database),
(ii) it also helps in organizing, sorting and retrieval of the
records/information from the database, when required by the user, to
help the user in decision making (management system).
DBMS MODEL
Benefits of DBMS:-
1.Faster storage and retrieval time
2.Accessing data is easy and fast
3.Data integrity(credibility of the data) and security. In govt.
offices, anyone can pick up any file! But DBMS requires password
authorization to access important files.
4.Backups and recovery are possible only in digital world, hence today
physical files are becoming extinct.
Points to remember in DBMS
1.In DBMS data are stored in relational model, using tables with rows
and columns (remember the steel racks!).
2.There are two types of Data Manipulation Languages (DML), Structured
Query Language (SQL) and Data Definition Language (DDL).
3.DML are computer languages also known as query language, it is used
for accessing and working on the data.
In other words, DML (SQL and DDL), are like the languages people use,
Hindi or English, in an office to give orders to the peon!
4.Data redundancy - which means there are no duplications of data. No
multiple files of the same kind.
5.Data dictionary - is like a normal dictionary, but containing metadata.
6.Metadata - contains information about all the data in the DBMS.
7.The Keys - Primary key is used to identify a particular or specific
record (file). It is unique to a particular file.
Foreign Key makes a connection between a component (field) in one
table with a component identified by a primary key.
8.Relational database - is the kind of database model, where there are
logical connections between the various files, which are kept in
tables.
For example: In the given diagram, the information is stored in tables
(with rows and columns), in this particular case in two relational
tables.
Every column has a Field name (employee ID, first name, last name,
e-mail ID, Department ID and Department name).
The relation between the two tables is created by the field
'Department ID', which connects the Employees name/ID/e-mail to a
particular Department like HR or software or accounts.
This is relational database, where a relation is made between items of
the database.
DBMS
That's all folks.
I am hoping that DBMS is no more vapour-ish but solid concrete! It can
not get simpler than this!
Keep learning and keep sharing the knowledge - that's the best way to
gain knowledge!
Get Bank Exams Study Notes HERE
--
nothing is difficult unless you make it appear so.
right place, etc. but more efficiently than a peon and faster too!!
I really do hope some vapour-ish ideas are forming in your head about DBMS!
Thus, putting down all our ideas in definition form - DBMS is a software,
(i) which helps a user in creating a collection of records and
information and storing them on the computer in a systematic way
(database),
(ii) it also helps in organizing, sorting and retrieval of the
records/information from the database, when required by the user, to
help the user in decision making (management system).
DBMS MODEL
Benefits of DBMS:-
1.Faster storage and retrieval time
2.Accessing data is easy and fast
3.Data integrity(credibility of the data) and security. In govt.
offices, anyone can pick up any file! But DBMS requires password
authorization to access important files.
4.Backups and recovery are possible only in digital world, hence today
physical files are becoming extinct.
Points to remember in DBMS
1.In DBMS data are stored in relational model, using tables with rows
and columns (remember the steel racks!).
2.There are two types of Data Manipulation Languages (DML), Structured
Query Language (SQL) and Data Definition Language (DDL).
3.DML are computer languages also known as query language, it is used
for accessing and working on the data.
In other words, DML (SQL and DDL), are like the languages people use,
Hindi or English, in an office to give orders to the peon!
4.Data redundancy - which means there are no duplications of data. No
multiple files of the same kind.
5.Data dictionary - is like a normal dictionary, but containing metadata.
6.Metadata - contains information about all the data in the DBMS.
7.The Keys - Primary key is used to identify a particular or specific
record (file). It is unique to a particular file.
Foreign Key makes a connection between a component (field) in one
table with a component identified by a primary key.
8.Relational database - is the kind of database model, where there are
logical connections between the various files, which are kept in
tables.
For example: In the given diagram, the information is stored in tables
(with rows and columns), in this particular case in two relational
tables.
Every column has a Field name (employee ID, first name, last name,
e-mail ID, Department ID and Department name).
The relation between the two tables is created by the field
'Department ID', which connects the Employees name/ID/e-mail to a
particular Department like HR or software or accounts.
This is relational database, where a relation is made between items of
the database.
DBMS
That's all folks.
I am hoping that DBMS is no more vapour-ish but solid concrete! It can
not get simpler than this!
Keep learning and keep sharing the knowledge - that's the best way to
gain knowledge!
Get Bank Exams Study Notes HERE
--
nothing is difficult unless you make it appear so.
--
Thanks and Regards,
Saranya S.
Thanks and Regards,
Saranya S.