Memory usage of ApplyLogOnInfo and TestConnectivity

Question

Hi,
Our application is coded in C++ (VS 2005)  and we access the Crystal Report 2008 API using .NET (CR 2008 SP1). In the application, when a report needs to be printed, it will
        Load the report
        Login to the database
        Set the parameters
        Print the report
        Close the report
        Perform garbage collection
One of our customers has a very large report (.rpt > 2 M), which has many subreports and each subreport accesses a number tables.While observing the memory usage from Task Manager on win 2008, I can see loading the report self eats up about 100 M, then Login to the database will consume another 400 M, when the Report is closed, the memoary drops back a little bit and stays at around 500 M. Re-run the same report again, the memory will go up by another 200 M mainly during the login step. Then it stays at around 700 M for subsequent printing requests.
For reports which are small (< 100 k) and do not have a lot of subreports, the memory usage will be around 150 M. I am wondering why the login step will use some much memory and they do not get freed up when the report is close for the second report request.
The following is the code for the login step:
void CRptWriterIntf::SetDBConnectionInfo()
     m_TableLogOnInfo = gcnew TableLogOnInfo;
     m_TableLogOnInfo->ConnectionInfo->DatabaseName = gcnew System::String(m_serverName.getBuffer());
     m_TableLogOnInfo->ConnectionInfo->ServerName = gcnew System::String(m_dbName.getBuffer());
     m_TableLogOnInfo->ConnectionInfo->UserID = gcnew System::String(m_dbUser.getBuffer());
     m_TableLogOnInfo->ConnectionInfo->Password = gcnew System::String(m_dbPass.getBuffer());
void CRptWriterIntf::ReportLogon(ReportDocument^ reportDocument)
     SetReportLogonInfo(reportDocument);
     for (int i=0; i < reportDocument->Subreports->Count; i++)
             ReportDocument^ subReport = reportDocument->Subreports<i>;
             SetReportLogonInfo(subReport);
void CRptWriterIntf::
SetReportLogonInfo( ReportDocument^ reportDocument)
    for (int i=0; i < reportDocument->Database->Tables->Count; i++)
        Table^ table = reportDocument->Database->Tables<i>;
        table->ApplyLogOnInfo(m_TableLogOnInfo);
        if (!table->TestConnectivity())
            LOG_ERROR();
            CleanEngine(reportDocument);
            throw e;
Thanks
Kin H Chan

Answer 1

Thank you for the suggestion.
I updated my Crystal Report 2008 to SP4, but that does not seem to make any difference in term of the memory usage.
I do not find any function to close the DB connection from the Crystal Report 2008 .NET API Reference. Am I missing something?
The Depose method is a protected method which I cannot access directly from the ReportDocument object. Instead, it will be called in the destructor of ReportDocument according to the documentation.
In my codes, after the report is generated, I always perform:
Close the report by:
     reportDocument->Close()
and
Perform garbage collection
     System::GC::Collect();
If I skip either one of the two calls below, the report will fail to access the db from the report
     table->ApplyLogOnInfo(m_TableLogOnInfo);
     if (!table->TestConnectivity())
That is the reason that I have them there. Are there alternative to this approach?
By the way, how can I attach file (e.g. screen shots, sample codes, sample reports) to my question?
Thanks
Kin H Chan