Select statement somtimes 'hangs'

[m.rup]

Hi,

I have a program which is refreshing it's data once per minute by a
select statement using an OracleDataSet from DOA tools v. 4.1.
The select is enclosed in an exception handling block.
In the majority of cases (e.g. session killed) the exception handling
works fine but under certain, unfortunately not reproducible
circumstances, the select statement will not come back and the complete
application freezes. Fortunately last time I noticed this happen I could
have virtually immediately a look at the database and saw that the
session had disappeared. In the log file written by the application the
last entry was 27.11.2007 16:16 (one line in code before the select
statement as expected).
I didn't kill the application and amazingly I found a second log entry
about two hours later (27.11.2007 18:17 ORA-03113: end-of-file on
communication channel) from within the exception handling.
It seems as if something happened on the client side after tis time.

So my questions are:

1. What could cause the standstill of the select statement (as I
wrote before I can't reproduce it, killing the session or pulling the
network cable always results in an exception)

2. How can I handle this? Can I give some kind of time out to the
session or the dataset?

Best regards

Martin

 

[Marco Kalter]

Apparently there is some condition where the Oracle Client waits indefinitely for a response from the Oracle Server, which never comes.

ORA-03113 usually means that the Oracle Server process for the current session has crashed. Can you check if a user trace dump file exist on the database server that corresponds to this ORA-03113 error? Usually you will see an ORA-00600 error here, with some error codes that may help us find the cause of the problem. If it does, can you send it to me?

 

[m.rup]

Thanks Marco,

I will send you a trace file via mail. This maybe will take some time because the problem occurs at random.

Martin