About empty (not null) fields size.

[nimapoggy]

Hi !
I would like to know how SQL server manage empty text fields. I heard that empty fields (not Null), in some other databases, were considered as non empty fields. For exemple, if I have a 200 chars long text field that I leave empty in some records, the space needed to store 200 chars was locker. So a database containing a lot of empty fields in records can be as big as if all the fields were not empty.
What about SQL server ?
If it's true, is there other data types such as INT that preserve its size even if it's empty ?

Note : I know the null value, but I'm trying to analyse an old database and I need some exemples to make understand that it was not well made...

 

[williamu]

In SQL Server NULL simply means that the data has not been defined. If you have a column of say varchar(200) then the space occupied by that field is equal to the size of it's contents.

A column char(200) will occupy 200 bytes of storage regardless of the length of the contents.

I hope this helps.

William
Software Engineer

 

[nimapoggy]

So, null is not a way to reduce database size in case of missing datas for such fields (char(200)) ?
Ok, so Thank you very much for your very usefull answer.
nico

 

[williamu]

No it isn't.

Sizing a database correctly (and optimally) is an 'art' in it's own right.



William
Software Engineer