Hi all, I am querying an SqlCe Database on my PDA and noticed that the device is slowly running out of memory every time I execute a query. I am using the following code:

public  SqlCeDataReader ExecuteReader(string command, params SqlCeParameter[] commandParameters)
        {
            SqlCeDataReader reader = null;
            SqlCeCommand c = new SqlCeCommand(command, cn);
            try
            {
                for (int i = 0; i < commandParameters.Length; i++)
                    c.Parameters.Add(commandParameters);
                reader = c.ExecuteReader();
            }
            catch
            {
                // Release resources
                c.Parameters.Clear();
                reader.Close();
                throw;
            }
            c.Parameters.Clear();
            return reader;
        }

This method is a part of my 'SqlCeHelper' class that I have written.

I noticed that when I reach the line reader = c.ExecuteReader() , the memory of my device decreases by about 1%. The reader is returned to a class which makes use of it and then disposes of it by calling reader.Close(); The connection to the database is also closed properly at some point, but memory never gets released. Memory gets only released when the application terminates.

I am wondering if I am doing something wrong by not disposing of some resources. Please help!

(Also tried GC.Collect() , didn't help!)

Cheers.

Hi,

first of all - thanks for your reply!

I have called reader.Dispose() and nothing really improved. In the class that uses the reader returned by the above method, the code is as follows:

IDataReader reader = null;

try

reader = _dbHelper.ExecuteReader("SELECT * FROM MeasurementInstance");

while (reader.Read())

if (reader != null && !reader.IsClosed)

...get relevant data from the reader and store it...

Are you actually running out of memory... getting a memory error?

Or are you just worrying about a memory leak?

I've noticed that with the PDA that memory is claimed and is not returned so quickly. However when it needs it the memory is returned. I have found no command such as Dispose... and dumping the garbage collection seems to not do much, if anything at all. However as stated I would still use the good programming practice of always dispose objects that offer 'dispose' as an option.

I've got an extensive application running on a PDA out in the field. The nurses often express complaints over slowness. I have them do a soft-reset periodically that seems to clean up things.

I believe that the memory leaks are due to the .NET system, or SQL Ce. I don't think we can do much about them, aside from a Soft-Reset... or a microsoft reboot...LOL

I hope that in the new version of SqlCe that these problems will not persist.