O'Reilly logo

Microsoft® SQL Server 2012 Unleashed by Alex T. Silverstein, Chris Gallelli, Paul T. Bertucci, Ray Rankins

Stay ahead with the world's most comprehensive technology and business learning platform.

With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, tutorials, and more.

Start Free Trial

No credit card required

Page Free Space Pages

A page free space (PFS) page records whether each page is allocated and the amount of free space available on the page. Each PFS covers 8,088 contiguous pages in the file. For each of the 8,088 pages, the PFS has a 1-byte record that contains a bitmap for each page indicating whether the page is empty, 1 to 50% full, 51 to 80% full, 81 to 95% full, or more than 95% full. The first PFS page in a file is located at page number 1, the second PFS page is located at page 8088, and each additional PFS page is located every 8,088 pages after that. SQL Server uses PFS pages to find free pages on extents and to find pages with space available on extents when a new row needs to be added to a table or index.

Figure 30.6 shows the layout ...

With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, interactive tutorials, and more.

Start Free Trial

No credit card required