Data storage

Data is stored in what are called as Pages, pages are of 8 Kilobytes.

Pages are then grouped in eight, which is called extent.

Significance of Extent : Whenever data is read, it is read in 64K size.

That means it grabs a complete extent.

Refer to below diagram.

Above image shows a single row being stored in a page. (Whole of the 8 K

is not available for data storage, some of it is used for house-keeping purpose)

Fill Factor

This parameter decides how much free space we have to keep in a data page, when

index are rebuilt.