We have installed DOA 4.0.7.1, and are developing against an Oracle 10G database. The application frequently fails with an ORA-24909 error message. After this message we need to restart the application. In one case we have solved the problem - a TOracleQuery was executed repeatedly without closing the query before repeating. I added a line to close the query, and this solved the problem. However it still appears in other situations. Before the actual oracle error message occurs, delphi reports an access violation "<my.exe> raised too many consecutive exceptions: 'access violation at 0x00000000 : read of adress 0x00000000'"

On MetaLink the only mention of ORA-24909 is the following:
"
Error: ORA-24909 (ORA-24909)
Text: call in progress. Current operation cancelled
---------------------------------------------------------------------------
Cause: The OCI call was invoked when another call on the connection was
in progress.
Action: Check if the OCI call is supported when the call is in progress
under special conditions; for example, if it is being used by a
signal handler. NLS_DO_NOT_TRANSLATE [24910,24910]

"

Do you have any suggestion / recommendation for us? If we always close queries before reopening them, wouldn't that lead to decrease in performance?

With regards,
Helene B. Halvorsen