RE: My ODBC concurrent Queries

Hi,
tell us a few more implementation details on your app: 
In particular, do your n threads share one common db-connection?
Do you use the same codebase for win & linux?

armin.


> -----Original Message-----
> From: J Jayavasanthan [mailto:[email protected]]
> Sent: Monday, May 25, 2009 12:50 PM
> To: [email protected]
> Subject: My ODBC concurrent Queries
> 
> Hi,
> In my application, the mysql server is connected via ODBC and we run
> multiple threads executing multiple queries with the mysql server.
> There is
> an issue in our application when we execute a bulk query (more than
> 100,000
> rows in resultset) and when the query takes a longer time for execute,
> all
> the other threads seem to just hang on their db operations.
> 
> We are even unable to get past the 'use database' query in most cases
> from
> other threads. Is this a limitation on the ODBC implementation in linux
> or
> have we failed to turn-on any options while building our ODBC drivers,
> do
> let us know.
> 
> In Windows, we are able to execute simultaneous queries using ODBC.
> This
> test environment uses all pre-compiled binaries from MySQL website.
> 
> In Linux, we are facing the above issues
> 
> Linux Flavor - Cent OS 5.2
> MySQL Server version - 5.1.30
> unixODBC version - 2.2.11
> myODBC version - 3.51.27
> 
> All Linux binaries are compiled in the same system as they are running.
> 
> When we execute two queries as separate processes (same executable
> started
> as different processes), we are able to do so. But, when we create two
> separate threads within the same process, then the above hang up
> arises. Is
> there any particular option in building our application we have missed,
> do
> let us know,
> 
> Regards,
> Jayavasanthan J