Search notes:
Oracle SQL Plan operation INDEX UNIQUE SCAN
In most cases, this plan operation has no child sources. The four rare row sources I have encountered so far include:
Among this operation's parent operator are
create table tq84_A (
nm number,
tx varchar2(200)
);
insert into tq84_A
select
mod(level * 773, 1009),
lpad('x', 200, 'x')
from
dual connect by level <= 1009;
create unique index tq84_A_uq on tq84_A(nm);
begin
dbms_stats.gather_table_stats(user, 'tq84_A');
end;
/
explain plan for
select
tx
from
tq84_A
where
nm = 500;
select * from table(dbms_xplan.display(format=>'basic'));
--
-- -------------------------------------------------
-- | Id | Operation | Name |
-- -------------------------------------------------
-- | 0 | SELECT STATEMENT | |
-- | 1 | TABLE ACCESS BY INDEX ROWID| TQ84_A |
-- | 2 | INDEX UNIQUE SCAN | TQ84_A_UQ |
-- -------------------------------------------------
drop table tq84_A;