Memory usage of SQL Server 2005 Mobile Edition

Hi forum readers,

we are working on a release 2.0 mobile solution right now. In our version 1.0 we did not have to worry about memory issues as our application was the only application running on our target devices (e.g. T-Mobile MDA Compact II Pocket PCs, WM2005).
Now we need to share the available memory with others. As our application relies on its SQL Server 2005 Mobile Edition database we are wondering about memory usage of that server.

We know that a Pocket PC divides its memory into Storage and Program. If our application uses a 5 MB database and 1.5 MB for DLLs and it's exe-file. These files reside in the storage space when not loaded. When the application starts up it is loaded in the program memory. What happens to the 5 MB database file? Is is loaded into Program memory as well? Are only portions of that file loaded? Or is nothing loaded at all?

Does anyone have a deeper insight into that server an can answer my questions.

Best regards,
Tobias

No, we don't load entire 5MB database into program memory. Only required pages are loaded to the buffer pool as and when required.

When database is loaded, lot of runtime structures are maintained for multi proc/thread synchronization. Some of these are maintained in shared memory. This total shared memory size figure is dependent mainly on the configurable parameters buffer pool size, max database size etc. If you increase them the figure goes up.

Assuming buffer pool size is the default (160 pages ~ 160*4096), we can roughly estimate the total size to be 800 KB + (max database size/1024) KB.

For ex: for a 60MB max size database, it would roughly 860 KB.

for a 2GB max size database, it would be roughly 2800 KB

Apart from this there would be a lot of other objects that are created & maintained as the client requests. For ex rowsets/cursors. It will be too difficult to estimate these as these are created based on the client code/usage.

Thanks - Raja

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Hi Raja,

Thank you very much, this gives us a better understanding of the required memory and the loading process.

Best Regards,

Tobias