Declaring a Number field with specific number of digits and without

Question

Hai Everybody.
I have a small doubt. At the time of creating a Table with column as Number data type, if i do not specify the length of digits, what it will take by default. What are the advantages and disadvantages of declaring the number field without specifying the length.
For example:
Create Table temp1 (col1 number);
Create Table temp1 (col1 number(6));
What is the difference between both the above statements. With the First Statement, what is the maximum number the table will accept.
Which one is better in terms of resource optimisation like alloting the memory space or processing speed or any other resources.
Pl clerify me.
Thanks
JD

Answer 1

Hi,
JayaDev(JD) wrote:
Hai Everybody.
I have a small doubt. At the time of creating a Table with column as Number data type, if i do not specify the length of digits, what it will take by default. What are the advantages and disadvantages of declaring the number field without specifying the length.NUMBER means any number (that Oracle can handle).
NUMBER (6) means an integer, with no more than 6 digits. If you INSERT 12.345, it will automatically get rounded to 12. If you try to INSERT 1234567, it will raise an error.
The default value is NULL in both cases, unless you specify otherwise.
>
For example:
Create Table temp1 (col1 number);
Create Table temp1 (col1 number(6));
What is the difference between both the above statements. With the First Statement, what is the maximum number the table will accept.In Oracle 11, the largest number is 9.99999999999999999999999999999999999999E+125, I believe.
Which one is better in terms of resource optimisation like alloting the memory space or processing speed or any other resources.NUMBER (6) is more efficient.
As in so many things, you get what you pay for. If you want the ability to handle larger or more precise NUMBERs, you pay for it in more storage space and less speed.
Read the pages that Karthick and Maktutakdu shown you.