Extent in Sql Server

 

Extent is bigger unit of Page. One extent contains 8 pages.
The size of the page is 8 KB. So the size of the extent is around 64 KB

 

Extent can be

  • MIxed Extent 
    • first eight pages of a table is stored in mixed extent.
    • Data from multliple tables can be stored in mix in asingle mixed content table i.e a single mixed extent, Pages have data from user, emails, employees etc

 

  • Uniform Extent 
    • Ffter eight pages a dedicated extent will be provided, which is known as uniform extent.
    • But after 8 from page number nine and onwards this is in a dedicated extent which is called uniform
    • Each single table data is dedicatly stored in respective unifrom page. i.e. after that 9 page number nine and onwards this is in a dedicated extent which is called uniform extent.

 

 


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