Yau, SYS(3050) controls the cache used for data operations. See

Memory Management in Visual FoxPro - MSKB#Q136694

and

Re: SYS(3050) Not Respected According to Task Manager Thread #728197 Message #728231

You might also might find this of interest:

How Visual FoxPro Memory Usage Affects Performance http://www.pinnaclepublishing.com/foxtalk/FTMag.nsf/Index/7AA27E67F86353B1852568E8007A53F1?opendocument


>Hi all,
>In order to reduce the default memory usage of my app written in VFP6 SP5, I use sys(3050) to limit the memory. (To about 1/3 the default value)
>When this is used, does it mean that regardless whatever the app is doing, the maximum memory that it can utilised is limited to what is defined by sys(3050).
>Would using this cause out of memory errors where heavy processing is involved?
>Some insights would be helpful.
>Regards
>Yau