MySQL Bugs: #47943: MySQL Update query

Bug #47943	MySQL Update query
Submitted:	9 Oct 2009 12:26	Modified:	9 Nov 2009 13:14
Reporter:	sampath kambar	Email Updates:
Status:	No Feedback	Impact on me:	None
Category:	MySQL Server: Query Cache	Severity:	S2 (Serious)
Version:	4.0.19	OS:	Windows (XP Professional, Service pack 2)
Assigned to:		CPU Architecture:	Any

Description:
Hi,

  We are facing a problem with Update query by Multiple threads.

  We have a Centralized MySQL Database, which has all user details(3 Lakhs).
  So more than one user can can have access to the DB( i.e Multiple threads will be accessing it).

 So, those threads will be trying to access the table and update 2  fields(One Integer value, One character ).

But what we are observing is Update Query is SUCCESS, but the value is not actually affected.Even we tried with mysql_affected_rows().

If we use some synchronization objects, then performance issues are arising.

Please suggest/help us.

Regards,
Sampath

How to repeat:
Try to update the same field, from Multiple threads.

For those who do not know the term 'lakh' I can tell it is an Indian term for "100,000".

@sampath .. almost nobody outside India know the terms 'lakh' and 'crore'.  Don't use them!

Thank you for the bug report. Please test with latest release and if continue the same issue provide a complete test case. Thanks in advance.

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".