How to avoid waiting forever when Updating a locked row ?

Hi all,
We have front-end application (ADF BC) on Oracle 10g database. From the adf we call stored procedure that execute the dml below :
UPDATE DOC_NUMBER SET doc_nbr = doc_nbr + 1
WHERE REGISTER = pRegsCode AND doc_code = pDocCode AND
loc_code = pLocCode AND
doc_year = vDocYear
RETURNING TO_CHAR(doc_nbr, '0000000') INTO vDocNo ;
Sometimes, this statement wait very long, I see in EM Top SQL that the Wait value = 99.66%. I assume this is caused by another user run same program and Not Commit.
So the question is :
1) How to make the 'UPDATE...' statement only wait 10 seconds, if fail to get the lock then time out ?
2) If a user run the stored proc and do not Commit, how to make the transaction 'Expires' after 10 seconds so that it does not block other users ??
FYI, the COMMIT part is not in the stored proc, it is done in ADF level.
That is why if there is error in ADF after executing the stored proc, the transaction left Uncommitted
Thank you very much for your help,
xtanto

This is not an Oracle issue and cannot really be sensible addressed (if at all) at Oracle level.
How is Oracle suppose to know that after 10 seconds (or minutes) to "expire" (rollback) all uncommitted transactions? This deals with the client side of the client-server. How to interact with the client. When to determine that the user on the client is idle. Etc.
There is no triggering/event mechanism I know of inside an Oracle server session that can be fired after the Oracle session has been idle for a period of time. The closest to that is DCD (Dead Connection Detection) - which is n.a. as the client is not dead, just idle.
The application controls and manages the the user interaction. It is in a far better position to realise that the user is not responding, and then to rollback its Oracle session.
This should be therefore done by the client and not Oracle. In its simplest form, you have a session handle in the client for your Oracle session. You create a global boolean variable (called something like openTransaction) in the application. This is set to TRUE when a transaction (e.g. select for update, insert, updare or delete) is started.
An application timer runs every n number of seconds. When it runs, it checks openTransaction. If true, it issues a ROLLBACK statement on that session handle.
This should do the trick.. in large hammer fashion way. Any such implementation will need careful thought and consideration of the actual business requirements and business process flow.
It is very seldom that in business, clerks John and Jane will be working with the very same client file/invoice/whatever at the exact same time. And when there is conflict, you want to make sure that either Jane or John works on that at a time.
So before even looking for a technical solution to your problem, I would first determine what the business process flow are and the boundaries of the business transaction, in order to realise a solution.

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8 /
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SQL> SHOW ERRORS;
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3    UNION ALL
4    SELECT 2, 'AB', .6 FROM DUAL
5    UNION ALL
6    SELECT 1, 'AC', .2 FROM DUAL
7    UNION ALL
8    SELECT 3, 'AA', 1 FROM DUAL
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10    SELECT 1, 'AA', .5 FROM DUAL
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Inserted Item for Category: 2
Inserted Item for Category: 1
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Inserted Item for Category: 2
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         1 AA         .5
         1 AC         .2
         2 AB         .4
         2 AB         .6
         3 AA          1
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SQL>
SQL> INSERT INTO item_t
2    SELECT 4, 'AB', .5 FROM DUAL
3    UNION ALL
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6    SELECT 5, 'AA', .5 FROM DUAL
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Initializing...
Inserted Item for Category: 4
Inserted Item for Category: 5
Inserted Item for Category: 5
Inserted Item for Category: 4
Inserted Item for Category: 4
Verifying...
Checking Category: 4
INSERT INTO item_t
ERROR at line 1:
ORA-20001: Category 4 total = 1.4
ORA-06512: at "PNOSKO.ITEM_AS_TRG", line 12
ORA-04088: error during execution of trigger 'PNOSKO.ITEM_AS_TRG'
SQL>
SQL> SELECT * FROM item_t ORDER BY category, item_code, pct;
CATEGORY IT        PCT
         1 AA         .3
         1 AA         .5
         1 AC         .2
         2 AB         .4
         2 AB         .6
         3 AA          1
6 rows selected.
SQL>

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