Updating records in batch

Question

Hi,
I have around 1 laks records in my database in one table.
I have to update one field of those records.
I do not want to update all records at a time, because its a production database.
There is no any range field avaialbe on that table.
Can somebody help me for doing this activity.
I want to update records in the batch, say of 500 or 1000.
Best regards,
Kiran

Answer 1

Why can't you just update all the rows? 100,000 rows isn't all that many these days, and Oracle locking is such that you would only lock users that were trying to update one of those rows, not insert a new row, for the length of the transaction. Is that really a problem? On my puny laptop, updating twice that many rows happens in 12 seconds
SCOTT @ jcave102 Local> create table a( col1 number );
Table created.
Elapsed: 00:00:00.12
SCOTT @ jcave102 Local> insert into a select rownum from all_objects;
42492 rows created.
Elapsed: 00:00:10.29
SCOTT @ jcave102 Local> insert into a select * from a;
42492 rows created.
Elapsed: 00:00:01.75
SCOTT @ jcave102 Local> insert into a select * from a;
84984 rows created.
Elapsed: 00:00:01.51
SCOTT @ jcave102 Local> commit;
Commit complete.
Elapsed: 00:00:00.01
SCOTT @ jcave102 Local> select count(*) from a;
  COUNT(*)
    169968
Elapsed: 00:00:00.04
SCOTT @ jcave102 Local> update a set col1=col1+1;
169968 rows updated.
Elapsed: 00:00:11.93If it is a problem, are you sure that other sessions reading data that's in the middle of being changed isn't a problem?
How will you handle the situation where your program dies in the middle? How will you know which rows have been processed and which have not?
Justin