Tag: page

• B+Trees – How SQL Server Indexes are Stored on Disk

  

  2014-06-18 - General, Series, SQL Server Internals, Storage Wednesday

  How does SQL Server organize clustered and non-clustered indexes on disk? SQL server uses B+Trees. Read on to find out what B+Trees are and how they are implemented in SQL Server.

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• DBCC FILEHEADER: Reading the File Header Page

  

  2014-05-21 - General, Series, SQL Server Internals, Storage Wednesday

  Every SQL Server database file has a dedicated file header page. Read on to discover how to use DBCC FILEHEADER to explore the header of your database files and learn about the one property of file header pages that might just affect your backup and restore strategy.

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• PFS Pages: How SQL Server tracks “Page Free Space”

  

  2014-04-30 - General, Series, SQL Server Internals, Storage Wednesday

  PFS pages contain information about the free space available on all pages in a database file. They contain one byte per page that also holds four additional status bits. Read on to discover how to interpret the PFS data.

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• The Shared Global Allocation Map (SGAM)

  

  2014-04-23 - General, Series, SQL Server Internals, Storage Wednesday

  Discover how SQL Server tracks mixed extents containing free pages using a Shared Global Allocation Map made up of one SGAM page per GAM Interval.

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• The GAM Interval and GAM Extents

  

  2014-04-09 - General, Series, SQL Server Internals, Storage Wednesday

  What is a GAM extent in SQL Server? What is a GAM Interval and how big is it really? Read on now to get the answers to these questions and see why a GAM interval is not 64000 extents.

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