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Q136694: Memory Management in Visual FoxPro

Article: Q136694
Product(s): Microsoft FoxPro
Version(s): 
Operating System(s): 
Keyword(s): 
Last Modified: 17-AUG-1999

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The information in this article applies to:

- Microsoft Visual FoxPro for Windows, version 3.0 
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SUMMARY
=======

This article describes memory management in Visual FoxPro. Memory is allocated
in a page pool and a handle pool.

MORE INFORMATION
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Handle Pool
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The handle pool contains memory that is used for various Visual FoxPro objects
such as windows, menus, classes, objects, cursors, sessions, and so on. Unlike
previous versions of FoxPro, this pool has no arbitrary limit. It is bound only
by the amount of virtual memory available from the underlying operating system
as set by the user using the operating system's virtual memory settings. Thus,
the size and complexity of a user's form or application is limited only by
available virtual memory, not available physical memory.

Page Pool
---------

The page pool contains memory used for file caching (to perform read buffering),
internal sorting, and query execution. For these purposes, it is critical that
the memory be physical, not virtual. In other words, Visual FoxPro needs memory
that won't be swapped to disk. While it can't guarantee this, it can try to
ensure this by limiting the size of the page pool so that it will all fit in
physical memory. The size of the page pool can also be set manually by using
SYS(3050).

Note that MEMLIMIT is not used in Visual FoxPro. The handle pool is limited by
available virtual memory, and the page pool can be dynamically resized using
SYS(3050).

Additional query words: VFoxWin crash insufficient RAM swapfile

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Keywords          :  
Technology        : kbVFPsearch kbAudDeveloper kbVFP300

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