0:06	hello everyone welcome back in this
0:08	presentation we will see the database
0:11	management system definition let's
0:13	directly step into the definition
0:15	a database management system simply dbms
0:19	is a collection of interrelated data and
0:23	a set of programs to access those data
0:26	if you observe the key term about dbms
0:30	is a collection of interrelated data so
0:33	database are going to store the data
0:35	obviously but it's not simply going to
0:37	store the data it's going to store the
0:40	interrelated data what is an
0:42	interrelated data if you can recollect
0:45	the previous example in the pencil
0:47	analogy which i was talking about you
0:49	can see that the data are actually
0:51	stored in the form of table
0:53	table means it's going to comprise rows
0:55	and columns say for example what are all
0:57	the data that are stored the color of
0:59	the pencil the model of the pencil or
1:01	pen the date of manufacturing etc if you
1:05	take a particular row the data stored in
1:07	that particular row are pertaining to a
1:10	pen or a pencil so the data are
1:12	interrelated to each other because it's
1:14	pertaining to a particular item and
1:17	that's why we say a database management
1:19	system dbms is a collection of
1:22	interrelated data and not only it is
1:25	going to store the interrelated data it
1:27	is also having a set of programs to
1:29	access those data because we obviously
1:32	need to access the data so if you are
1:34	going to an atm machine to withdraw some
1:36	money when you insert your card into the
1:38	atm machine obviously your details have
1:41	to be fetched from the database where
1:43	the database are the central entity that
1:45	stores all the information about all
1:48	customers so this database may be in a
1:50	remote location all your required data
1:53	is fetched and it is now given into the
1:55	atm machine now atm machine is actually
1:57	displaying that information for you so
2:00	from this we understood that databases
2:02	are not only for storing purpose it is
2:04	also for retrieving or accessing purpose
2:08	so this is what the definition of
2:10	database management system
2:12	we have just seen the definition of dbms
2:14	let's now see various points about dbms
2:17	for better understanding when we talk
2:19	about additional points about dbms we
2:22	need to clearly understand that the
2:24	primary goal of dbms is to store the
2:27	data and retrieve the data so dbms
2:30	should facilitate us to store the data
2:32	easily and effectively at the same time
2:34	whenever we require the data it should
2:37	have the set of programs to retrieve the
2:39	data easily so simply storing and
2:42	retrieving should be convenient and it
2:44	also should be efficient because the
2:47	fact is when we store and retrieve the
2:49
data in the files we are not achieving
2:52
efficiency and convenience when we do
2:54
that with the file system
2:56
don't worry about this now anyway in the
2:58
coming lectures we are going to see the
3:01
advantages of having dbms over file
3:03
systems from the last presentation we
3:06
confirmed that any organization needs
3:08
databases when organization needs to
3:11
store all the information possible
3:14
think about the volume of the
3:15
information that organization is going
3:17
to store
3:18
it's obviously huge enormous right so we
3:21
need to have database management system
3:24
that can manage large bodies of
3:26
information see any data it should store
3:29
whether you edit the data or whether you
3:31
delete the data if you want to be
3:33
transparent and accountable obviously
3:35
all data have to be stored including all
3:38
transactions what we make must be
3:40
recorded only then we can reap the real
3:42
power of having database management
3:45
system and we can understand that we are
3:47
going to manage large bodies of
3:50
information and obviously we need to
3:53
define the data storage structures
3:55
because databases are not going to store
3:57
only simple data types it's going to
3:59
store enormous data say in certain
4:02
situations we need to store multimedia
4:04
data also where the database is going to
4:06
store the audio data video data
4:09
animations and whatnot so in such a case
4:12
we need to define the appropriate data
4:14
storage structures it may be a simple
4:16
data structure or even it may be a
4:18
complex data structure ultimately we
4:21
want to store all the data in the
4:23
database management system and we
4:25
understood that we are going to store
4:27
the data and we are going to retrieve
4:29
the data effectively and not only this
4:32
we need to have few mechanisms for data
4:34
manipulation we may be in a need to edit
4:37
the data for example you wanted to
4:39
change your existing information you
4:41
might have relocated to a new residence
4:43
or you might have changed your phone
4:45
number say the databases must be updated
4:47
with the accurate and the correct
4:49
information so in such a case dbms
4:52
should have the mechanisms for data
4:53
manipulation
4:55
and is that all fine
4:57
no we need to focus on one of the
4:58
important aspects the safety and
5:00
security of the information store we
5:03
know databases are going to store the
5:05
data and we need to focus on the safety
5:09
and security of the data or the
5:11
information stored so database should
5:13
have the mechanism to protect the data
5:15
if you keenly observe i am using the
5:18
terminologies like data and information
5:21
can they be used interchangeably or is
5:23
there any difference between data and
5:25
information that's what we are going to
5:27
see now we will see data versus
5:30
information what is actually data
5:33
data is plural and datum is singular
5:36
when we have collection of datum this is
5:38
referred as data anything in this world
5:41
can be described as data take anything a
5:43
simple chalk piece for example if you
5:46
take chalk piece as an example what are
5:48
all the things that we can describe
5:49
about the chalk piece the length of the
5:51
chalk piece the color of the chalk piece
5:53
the lifetime of the chalk piece the
5:55
width of the chalk piece and many more
5:57
all these are data in this world
6:00
everything is of data even birth and
6:02
death has data so i mean to say the data
6:06
means it's the raw piece of information
6:09
or the unprocessed facts say for example
6:12
25 raga nagpur all these items are data
6:18
they are raw information raw facts
6:20
raghav is the name of the person nagpur
6:23
is the name of the city 25 is a number
6:26
this 25 may be anything it may be the
6:29
age of the person or it may be the
6:31
account balance of that person or it may
6:33
be the door number this is a raw fact
6:36
and that's why we call these unprocessed
6:38
facts or raw facts as data then what is
6:41
an information an information is the
6:44
processed data for example we have the
6:46
data here now we are going to process
6:49	this data so that we are getting an
6:51	information the information is the age
6:54	of raga is 25 who is residing in nagpur
6:58	so what do we mean by this
7:00	we had the raw facts which is the raw
7:03	data now we have the processed data
7:06	which is actually the information the
7:08	age of raga is 25 and raghav is actually
7:11	residing in nagpur
7:13	i hope now things are clear to you and
7:16	what about databases are databases
7:18	collection of data
7:20	no please be noted that databases are
7:23	not simply collection of data databases
7:26	are collection of interrelated data for
7:29	example whatever we do in the real-time
7:32	banking world or the library management
7:34	or railways everything is going to store
7:37	the data in the form of tables to be
7:40	precise rows and columns so databases
7:43	are the collection of interrelated data
7:46	and also database management systems are
7:48	a set of programs to access those data
7:50	efficiently before we sign out let's see
7:53	one more key point the metadata metadata
7:56	means data about other data say for
7:59	example if you are creating a file where
8:01	our information is going to be stored in
8:03	the file and what are all the other data
8:05	that describes about this file we know
8:07	file is storing all the data a file
8:09	itself is the data
8:11	now the other information about the file
8:13	like the author information who created
8:16	the file the date created the date
8:18	modified the file size all these
8:21	information are the data that is
8:23	describing about other data right so
8:26	these data are generally referred as the
8:28	metadata so what we have learnt in this
8:31	presentation we have learnt about the
8:33	formal definition of dbms we have seen
8:36	some points about databases we also have
8:38	seen the difference between data and
8:40	information we also have seen about
8:42	metadata and that's it guys
8:45	i'll see you in the next presentation
8:47	thank you for watching
8:49	[Applause]
8:52	[Music]
9:00	you