There is one more condition under which this becomes useful. Suppose you have requirements for setting transaction isolation level as serializable only for select statements, you can avoid setting the transaction isolation level as serializable by making use of this feature. any expert comments?
There is only one condition under which this would be useful.
Current Scenario:
BEGIN
Select x into var from inventory where y=const;
update inventory..
some more DMLs.
some select into var2;
if (condition based on var2) use the var;
END;
here i have to fire the first select query all the 100% of the time. Say if i have a feature to time travel within a transaction, i need to fire that select query on the probability of the condition based on var2 getting true.
After that implementation
BEGIN; store command id and increment it into cid; some DMLS some select into var2 if(condition based on var2) select into :var as of cid;
I know this is a small use-case. But if you think about it, the implementation is very easy. It wouldn't take much time to implement it.
