Best way to update an OLTP table ?

Question

Hi,
We have an OLTP table with huge data.
We need to update a status column from 'N' to 'Y' for almost 70% of rows based on some condition.
This table may be accessed by hundreds of sessions at a time.
So, what is the best way to do the same.
Rgds,
Rup

Answer 1

if someone is using the table, ddl cannot be done (or at least you would have to wait maybe a long time)
quick test...
SQL> create table bank
  2  (id number primary key
  3  ,acc number
  4  ,ind varchar2(1)
  5  )
  6  /
Table created.
SQL> insert into bank
  2  select rownum
  3       , rownum * 10
  4       , 'N'
  5    from all_objects
  6   where rownum <= 10
  7  /
10 rows created.
SQL> commit;
Commit complete.
SQL> update bank
  2     set acc = -10
  3   where id = 10
  4  /
1 row updated.new session
SQL> alter table bank
  2  add new_ind varchar2(1)
  3  /
alter table bank
ERROR at line 1:
ORA-00054: resource busy and acquire with NOWAIT specifiedwell, not a long time... but anyway you can't do ddl while someone is working on the table.