Oracle: Primary key constraint

Naming the index of the primary key

create table tq84_tab (
   id   number /*not null*/,
   val  varchar2(10)
);

create unique index tq84_tab_ix on tq84_tab(id);

alter table tq84_tab add primary key (id);

drop  table tq84_tab;

create table tq84_tab (
   id   number
           constraint tq84_tab_pk primary key
           using index (
             create unique index tq84_tab_ix on tq84_tab(id)
           ),
   val  varchar2(10)
);

Dropping the primary key, but keeping the index

alter table tq84_tab drop constraint tq84_tab_pk keep index;
select * from user_indexes where table_name = 'TQ84_TAB';

Dropping tables referenced by other tables

RELY

alter table tq84_table
  add primary key (
    col_one,
    col_two
  )
  rely
  disable;

See also