Windows Memory Rights - SQL-FineBuild/Common GitHub Wiki

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This section describes the Windows Rights that affect SQL Server memory management.

This section covers the following items:

A number of other Windows Rights exist that are not relevant for SQL Server memory management.

Lock Pages in Memory Right

The Lock Pages in Memory Right will let Windows honour an API call from a program to reserve a range of memory for its exclusive use.

If Windows runs short of memory, it uses a multi-stage process similar to that shown below to reclaim memory from programs. If enough memory is reclaimed at the end of a given stage, the following stages are not processed:

  1. Non-essential program and Windows memory is moved to the Windows Page File

  2. Programs with locked memory are asked to release it, but each program can decide if it will honour the request

  3. Locked memory is reclaimed by Windows, regardless of if a program wishes to release it

  4. In-use program memory is reclaimed by Windows

  5. Private Work Set memory is reclaimed by Windows

  6. Snap Dump and Reboot process starts

When memory is reclaimed by Windows, this can severely slow down or even stop the affected program from processing. It is therefore important to avoid over-committing memory, so that the performance of SQL Server is not put at risk by memory stortages.

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Recommendations for Windows Memory Rights

The recommended settings for the Windows Memory Rights described on this page are given below:

  • The Lock Pages in Memory Right should always be granted to the account running the SQL Server database engine. SQL FineBuild will always grant this right.

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