Bug #39638 Datareader Hangs on Large Databases and Complex Queries
Submitted: 24 Sep 2008 21:56 Modified: 30 Oct 2008 5:52
Reporter: Michael Johnson Email Updates:
Status: No Feedback Impact on me:
None 
Category:Connector / NET Severity:S1 (Critical)
Version:5.2.3. OS:Windows
Assigned to: CPU Architecture:Any
Tags: .net Connector, DataReader, hang

[24 Sep 2008 21:56] Michael Johnson
Description:
Datareader hangs on larger databases when performing complex queries.  There is never an exception thrown.  I've had this happen on queries where there are multiple joins with a fair number of rows.  However, when the reader is using a simple single table query, have never had this occur.  

I'm able to repdouce this consistenly, however, reader is not consistent in terms of where it dies in the number of records read.  Sometimes it might be at 27,000 while other times it makes it to 112,000 records (numbers are purely representative). 

I have confirmation from Microsoft technical support (who originally looked into this and evaluated the memory dumps) that the .NET framework is waiting on the mysql.data.dll to return data when it hangs.  

How to repeat:
Sample project available upon request, along with the database that this exhibits itself on.  

Suggested fix:
Provide full dataset back consistently
[29 Sep 2008 14:28] Tonci Grgin
Hi Michael and thanks for your report. However I have nothing to work with... No code, no databases, no MySQL server info, no error logs... nothing. Personally I tested this functionality more than once, with and without compression and it worked fine.

As for urgency, you will need support contract. Not that it can help you with such "it does not work" kind of report.

So please attach code and database and add as much info as you can if you want me to start working on your report.
[29 Sep 2008 15:38] Michael Johnson
Tonci,

Will prepare project and attach both code and database as soon as I have it ready for you.  Aplogoize for not putting this upon the first submission. 

Michael
[30 Sep 2008 5:52] Tonci Grgin
Michael, no problem, I just wanted you to realize I have nothing to work on. Waiting on your test case.
[1 Nov 2008 0:10] Bugs System
No feedback was provided for this bug for over a month, so it is
being suspended automatically. If you are able to provide the
information that was originally requested, please do so and change
the status of the bug back to "Open".