Oracle Datatypes
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==> Datatypes are used to specify the type of the data which required to write the column of the table.
==> In the oracle, the datatypes are represented with different types:
	1) Number type
	2) Text type
	3) Date type
	4) Timestamp
	5) Other special datatypes or Miscellaneous types

Number Types:
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	byte, short, int and long ==> whole numbers
	float and double ==> fractional numbers
	char and boolean
=> Any number like: whole number, zero value, +eve value and -eve values along with these we can also represent floating-point and double values using "number" type.

Ex: 1.23, 12, -123 etc.

==> The number type can be used in different ways:
1) number(size):
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-> this can be used to assign only the whole numbers.
here:
	size ==> the number of digits.
Ex: studentRoll number;
studentRoll ==> 1234567890;

Note: when we are not specifying the size, then the number of digits are completely based on the system configuration.
In general we can allow to write up to 24-digits for any system configuration.

Ex: employeeId number(5);
employeeId = 93457;
employeeId = 123

Here: the length of the number should not be exceeded the given size.
And we allowed to define the length of the number up to the size. 

2) number(precision, size):
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-> this can be used to define the "fractional values" or "decimal point vales".
Here:
	precision ==> describing the total decimal literals of the fractional number.
	size ==> the total digits after the decimal point.
Ex: 1234.50 ==> number(6,2)

Ex: Salary number(8,2);
Salary = 100000.50

2) Text type:
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=> three different types of text types:
	1) char(size)
	2) varchar(size)
	3) varchar2(size)

1) char(size):
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Ex: grade char(1);
emploeeName char(30);
employeeName = 'ravi';

=> here, the oracle assign the memory based on the size.
If the size = 30
==> memory ==> 30-bytes
and the value ==> "ravi"
out of the 30-bytes only 4-bytes can be used to write the above value and remaining 26 are wasted.
==> The memory representation for char(size) is "static way".
==> The maximum capacity ==> 2000 characters 

2) varchar(size):
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==> introduced by "SQL".
==> maximum capacity ==> 4000 characters
==> the memory assignment for varchar is always in dynamic nature.

Ex: employeeName varchar(40);
employeeName = "ravi"; ==> 4-bytes

3) varchar2(size):
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==> is same as "varchar"
==> is introduced by "oracle corporation".

3) Date type:
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-> default format for the date is: "dd-Mon-yy"

Ex: employeeDateOfJoin date;
employeeDateOfJoin = "15-May-25";

=> to get the system date, we can use the below query:
	"select sysdate from dual"

4) Timestamp:
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==> default representation for the timestamp is:
	"dd-Mon-YY HH:MM:SS"

5) Special Datatypes:
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1) clob ==> Character Large Object => when we need to handle the data above 4k capacity
Ex: employee History,
 Student Data etc.
=> capacity: 1 G to 4 G

2) blob ==> Binary Large Object
	=> to deal with files like: audio files and or video files ==> blob is used.
	==> capacity : 1 to 4G

3) BFile ==> Binary File
	same as blob