Sorry sent to wrong list. My apologies.

Rob Martin
Software Engineer

phone +64 03 377 0495
fax +64 03 377 0496
web www.chreos.com

Wild Software Ltd



Robert martin wrote:

>Hi
>
>We are converting an old BDE based application to Firebird. Are using
>the IBODatabase and TDataset descendant components to speed conversion.
>At the moment we are using the default transaction in the IBODatabase
>component with isolation set to tiCommitted and AutoCommit set to true.
>
>We have just converted a larger user who is getting the following error
>messages some times...
>
>
>ISC ERROR CODE:335544345
>
>ISC ERROR MESSAGE:
>lock conflict on no wait transaction
>deadlock
>update conflicts with concurrent update
>
>STATEMENT:
>TIBOInternalDataset: "<TIB_Session>.<TwsQuery>.<TIBOInternalDataset>."
>
>.
>
>TwsQuery is a class descended from TIBOQuery.
>
>I think I have tracked the code to and area where the following occurs.
>
>-Get a list of tables / records to delete
>
>SELECT *
>FROM WorkControl
>WHERE Status = 'D'
>
>....
>
>- Build a string list of tables related to the current transaction then
>loop though them, deleting assoicated reocrds
>
>UpdateQuery.SQL.Text := 'DELETE FROM ' + TablesToDelete[LoopCount] + '
>WHERE ControlRef = ' + FieldByName('ControlRef').AsString + ';';
>UpdateQuery.ExecSQL;
>
>- Delete stuff from WorkControl
>DELETE
>FROM WorkControl
>WHERE Status = 'D'
>
>My question really is, fir two people try the above delete SQL at the
>same time will this cause a 'Deadlock' and if so how do I get around it?
>
>TIA Rob
>
>
>
>
>