Does Null Occupy space in SQL Server

Question

Hi Does NULL occupy space in SQL Server? Thanks -- Vijaya Kadiyala http://www.dotnetvj.com

Niradhip Chakraborty · Answer

The fact that the field is null is saved in a null-bit-mask that contains the Null-yes/no (1/0) for all nullable fields. so by defining a field to be nullable you will request 1 bit in such a bit-mask to be used for all rows. The bit-mask is however increased to 8 bits modularity

Vijaya Kadiyala · Answer

Hi Niradhip Thanks for the explanation. Mahesh Till now i even didn't know about. I got this question from beginer :) wow...i couldn't his question at first. Thanks -- Vijaya Kadiyala www.dotnetvj.com

Mahesh Chand · Answer

Nice thread. I didn't know that much about Null in SQL Server ;) Thanks guys!

Vijaya Kadiyala · Answer

Hi Thanks for your prompt reply. 2-3 bytes is unique for every datatype? it changes based on the data type. Thanks -- Vijaya Kadiyala www.dotnetvj.com

Niradhip Chakraborty · Answer

Virtually no space is needed if there is no data (but internally it need 2-3 bits if it is a NULLable field )