Bug #7796 Concurrent Update not Thread Safe
Submitted: 11 Jan 2005 10:05 Modified: 3 Apr 2005 6:49
Reporter: Leo Chan Email Updates:
Status: No Feedback Impact on me:
None 
Category:MySQL Server Severity:S1 (Critical)
Version:4.1.8 OS:Linux (Red Hat Entripise Server 3.0)
Assigned to: CPU Architecture:Any

[11 Jan 2005 10:05] Leo Chan
Description:
I have a table with a column is tinyint.  I continous run ~50 update/sec by the following sql "update record=record+1 where my_pk='xxxx' ";  After I run for about 1000000 times and I found one update is missing. My client app also log down the affected rows and all is "1";  My client is java app by using jdbc with J-Connector (3.0.16) to run the sql.   I can found it missing as my client app will log out the sql statement into the log file.  The table I using is "HEAP" and concurrent record in the table <1000;

How to repeat:
create a table(HEAP) with simple pk and another column in tinyint. Concurrent insert, update (column(tinyint) = column(tinyint) +1 )and delete some records for running many hours.
[3 Mar 2005 6:49] Jorge del Conde
Hi!

Can you please create a C written test-case that demonstrates this behaviour ?

Thanks a lot.
[3 Apr 2005 23:00] 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".