I want to write program that use procedure in pl/sql to update table by 2 condition below,
1.update table x set x.a=(select y.a from y
where y.b=x.b)
if y.a is null then update table x set x.c=1,
2.update table x set x.d=(select z.d from z
where z.g=x.g)
if z.d is null then update table x set x.c=2

this program will update about 100000 rows.
how I write program that good performance, help me please?

Thank you for your help very very much

Do you need the logic or do you need to know how to effeciently update 100000 rows? I would use bulk binds to update those many rows. It uses the native pl/sql engine and the updates are much faster.

Thank you for your reply.
I'm use pl/sql at first time I'm a beginner,so I want to know both logic and need effeciently.
Can you guide me how to write program with condition that I post or can you coding example of program!

Thank you,

If you can post the pseudo code or logic, I can help you write the pl/sql code. And then, show you how to write it using bulk updates.

In the meanwhile, you can start reading some book on pl/sql or the documentation at http://tahiti.oracle.com