Memory Management

[robertx]

I have developed a DB app using Access, VB6, ADO, VB data reports. One user is getting RTE 7 (Out of memory errors) with WIN98 and 128MB RAM.

I have done all of the obvious things - closed recordsets, kept vars local, set forms to nothing when closing etc.

I cannot reproduce the error on WIN2000, 256MB RAM. I downloaded a "memory monitor" from a previous thread so that I could see when chunks of RAM were being consumed by my app. I notice that when data reports are run that up to 8MB of RAM is consumed but not reclaimed when the report is closed. When I was close to consuming all of my RAM, I opened IE (to try to crash my app) but WIN2000 found "virtual memory" and the available RAM jumped back to 170MB.

How can I reclaim memory after reports have been run and closed?
What is Virtual RAM? Is this new to WIN2000?
If I have a form and set it to nothing, is the memory occupied by module level vars freed?

[phinds]

virtual RAM has been around since DOS days. It's a disk swap file that lets the system act as though it has more memory than it has, by using the disk as additional memory. If you have an app that does a lot of swapping in/out of virtual memory, you'll notice a performance drop, but for most users/applications, the issue never comes up as a problem since any swapping that occurs happens only once per app. In the early DOS days, this was know as the "overlay file" but since then it has been called "virtual RAM"