'Examples of deadlocks in APEX

For a school assignment I need to simulate a deadlock in the UI of my APEX application. I know how a deadlock works and why it occurs, but I cannot figure out how someone would simulate a deadlock in an APEX application.
Keep in mind, I don't mean the SQL editor in APEX, but the actual app builder.

When would one start a transaction and how would it occur that a started transaction would run long enough for another transaction to cause a deadlock.

Hope someone could help me because I really do not know how I would simulate such a case.

Thanks.

oracle-apex


Solution 1:[1]

Setup:

create table T as select 0 x from dual union select 1 x from dual;

Then on a button press, have the following PLSQL code:

delete from t where x = :item;
dbms_session.sleep(30);
delete from t where x = (1-:item);

Then fire up two APEX sessions:

  • Session1: Set :item to 0 and click the button
  • Session 2: Set :item to 1 and click the button

Sources

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Source: Stack Overflow

Solution Source
Solution 1 Connor McDonald

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