How varchar data is stored?

In SQL Server we use varchar, varbinary to save disk space in our tables. But its not saving data always as it sounds. When the data stores it takes few extra bytes to describe the data length. Because of that there is no gain using varchar(2). If you use varchar(2) it will take 4 or 3 bytes to store data. varchar(8000) or below should have 2Byte offset to store the variability of character count. If you are using varchar(max) is different. It should have 4 Bytes offset. But I’m still looking for that to confirm it takes 4 Bytes. And it is stored in Variable Column Offset Array.

062911_1840_Themysteryo1

Picture: http://www.sqlservercentral.com/blogs/aschenbrenner/2011/06/29/the-mystery-of-the-null-bitmap-mask/

Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s