I have table
create table1( column1 number(10, column2 number(10), column3 number(10) );
column1 is Primary Key
column3 is Foreign key
I have created unique constraint on 2 columns
alter table table1 add constraint table1_contr1 unique(column1,column2) using index tablespace tbs1;
when I went to create index on both columns as
create index table1_idx1 on table1(column1,coulmn2); ERROR at line 1: ORA-01408: such column list already indexed
So Oracle already created index when I create unique constraint. But if I create index separately it is accepting those
create index table1_idx1 on table1(column1); create index table2_idx2 on table2(column2);
Now my question is, after having unique constraint on both columns do I still need to worry about creating an index on each column? Will omitting the single column indexes have an impact on performance while querying the table?
It's on oracle 11R2.