DATA PAGES AND EXTENT IN SQL SERVER 2005
In SQL SERVER data is stored in the form of data pages.Each data page is of size 8 KB. 8 data pages makes 1 extent.
This means 1 EXTENT = collection of 8 Data Pages.
Types of Extents.
Uniform extent contains all the data pages of single object. Mixed extent contains data pages of multiple objects. By default first mixed extent is created beacuse we dont know the fields are from the single object or not.If all the fields in mixed extent are from the single object then it converts it to Uniform.
DATA FILE <– Collection of Extents
EXTENT <– Collection of 8 Pages
DATA PAGES <– Collection of records