Taking off a Primary Key

Question

Hi ,
I have created a table with a P.K and analyzed it
i know when i define a primary it is autoamatically indexed BUT
if i take off the P.K , would it actually affect the execution plan ?
pls advise
tks & rdgs

Answer 1

Assuming that Oracle created a new index to enforce the primary key constraint
(it could have used an existing index), removing the primary key would remove
the indexActually the same is true even if Oracle uses an existing index....
SQL> create table pk_tab (col1 number not null)
  2  /
Table created.
SQL> create unique index tab_i on pk_tab(col1)
  2  /
Index created.
SQL> alter table pk_tab add constraint  tab_pk primary key (col1) using index
  2  /
Table altered.
SQL> select index_name from user_indexes
  2  where table_name = 'PK_TAB'
  3  /
INDEX_NAME
TAB_I
SQL> alter table pk_tab drop primary key
  2  /
Table altered.
SQL> select index_name from user_indexes
  2  where table_name = 'PK_TAB'
  3  /
no rows selected
SQL> Cheers, APC