improving performance of update statement

[tamilselvan]

Do it in a single shot (SQL).
See below:

set time on timing on
spool upd_my_table_2.log

drop index scott.my_table_m3 ;

--- 1 option
alter table scott.my_table parallel 8;
alter index scott.my_table_p1 parallel 8;
alter table scott.tamil_temp_con_addr parallel 8;
alter index scott.tamil_temp_con_addr_idx parallel 8;

commit;
alter session enable parallel dml ;
alter session enable parallel query ;

update /*+ parallel(a,8) */ scott.my_table a
   set a.pr_addr_id = ( select addr_per_id
                          from scott.tamil_temp_con_addr c
                         where c.accnt_id = a.row_id)
where exists ( select null
                from scott.tamil_temp_con_addr c
                where c.accnt_id = a.row_id) ;
commit;
alter session disable parallel dml ;
alter session disable parallel query ;
alter table scott.my_table    noparallel ;
alter index scott.my_table_p1 noparallel ;

spool off 

Tamil