Internal processing of in operator

Question

Hi,
I'm having some doubts here regarding internal processign of IN operator.
My doubt here is whether in the IN operator the processing of the rows(internally) is done 1 by 1(based on the connditions) or its executed in single shot?
for example, if we give
update abc set xyz=2 where i in (1,2,3);
Here, the execution will be done one by one for 1,2, & 3 or all the records will be updated in a single shot internally?
Thanks
Deepak

Answer 1

My question here is whether the statement will fetch values differently for each value in IN operator and update one by one or it will fetch all the combinations inside IN operator and fire a bulk update on all the records affected.
for an example see below query:
update abc set x=1 where xyz in(1,2,3)
My doubt here is whether Oracle internally will perform like below
update abc set x=1 where xyz =1 --------total 10 rows
update abc set x=1 where xyz =2 --------total 15 rows
update abc set x=1 where xyz =3 --------total 20 rows
or it will collect all the 45(10+15+20) rows and perform a bulk update on that?
My question here belongs to the internal processing of oracle, not on what we get on screen.
Hope I'm clear with my requirement. Please let me know in case of any other issues.
Thanks
Deepak