Update nowait only with for update?

Question

Hello,
Aparently there is no "nowait" option for simple sql update statements. It exists only in "select .... for update nowait".
As oracle does a implicit row lock anyway upon execution of a normal update statement, i thought it would be handy
if I could write the following statement in order to not have to wait if another session is locking the current row:
update my_table set attr_y = 'val_z' where my_key = 123 nowait;
As this doesn't exist, I tried the following:
declare
v_key number;
begin
select my_key into v_key from my_table where my_key = 123 for update nowait;
update my_table set attr_y = 'val_z' where my_key = 123;
commit;
end;
When I block this record with another session (update without commit), this perfectly works,
I get the desired exeption.
Now this is probably not "the way to do this". Are there any other solutions?
Thanks for any help,
Martin

Answer 1

What you are performing is typically called "pessimistic locking"
Tom elaborates a bit on the differences between optimistic and pessimistic. Either approach is valid and can be used.
http://asktom.oracle.com/pls/asktom/f?p=100:11:0::::P11_QUESTION_ID:5771117722373
"Now this is probably not "the way to do this". Are there any other solutions?"Do a bit of further reading and find out if what you apply is appropriate
http://www.orafaq.com/papers/locking.pdf
Also, this might be useful
http://download.oracle.com/docs/cd/E11882_01/server.112/e10713/consist.htm#insertedID0
before reading any of the others.