Date Data difference from table

Question

DB : 11.1.0.7
I have one table and it has date column without time information. I would like to retrive data for missing consecutive dates more than 2 days.
For Eg.
Select * from xyz
location date
1 05/10/2011
1 04/10/2011
1 01/10/2011
1 30/09/2011
1 27/09/2011
2 04/10/2011
2 01/10/2011
2 30/09/2011
3 04/10/2011
3 01/10/2011
3 30/09/2011
3 29/09/2011
3 26/09/2011
3 25/09/2011
Looking for output be like below.
Location Missing Date
1 04/10/2011
1 30/09/2011
2 04/10/2011
3 04/10/2011
3 29/09/2011
Any suggestion ?

Answer 1

with sample_data as (
                     select 1 location ,to_date('05/10/2011','dd/mm/yyyy') dt from dual union all
                     select 1,to_date('04/10/2011','dd/mm/yyyy') from dual union all
                     select 1,to_date('01/10/2011','dd/mm/yyyy') from dual union all
                     select 1,to_date('30/09/2011','dd/mm/yyyy') from dual union all
                     select 1,to_date('27/09/2011','dd/mm/yyyy') from dual union all
                     select 2,to_date('04/10/2011','dd/mm/yyyy') from dual union all
                     select 2,to_date('01/10/2011','dd/mm/yyyy') from dual union all
                     select 2,to_date('30/09/2011','dd/mm/yyyy') from dual union all
                     select 3,to_date('04/10/2011','dd/mm/yyyy') from dual union all
                     select 3,to_date('01/10/2011','dd/mm/yyyy') from dual union all
                     select 3,to_date('30/09/2011','dd/mm/yyyy') from dual union all
                     select 3,to_date('29/09/2011','dd/mm/yyyy') from dual union all
                     select 3,to_date('26/09/2011','dd/mm/yyyy') from dual union all
                     select 3,to_date('25/09/2011','dd/mm/yyyy') from dual
select  location,
        dt missing_dt
  from  (
         select  location,
                 dt,
                 dt - lag(dt) over(partition by location order by dt) gap
           from  sample_data
  where gap > 2
  LOCATION MISSING_D
         1 30-SEP-11
         1 04-OCT-11
         2 04-OCT-11
         3 29-SEP-11
         3 04-OCT-11
SQL> SY.