SQL Oracle Counting Clusters

Question

I have a data set which is based on a timestamp.

     Date                 Value
07-Jul-15 12:05:00          1  
07-Jul-15 12:10:00          1 
07-Jul-15 12:         


        

Answer 1

Using LEAD and LAG functions in ORACLE you can built these queries:

1.Number of shutdowns:

WITH IntTable AS
( SELECT * FROM
  (
   SELECT dt b_date,value,LEAD(dt) OVER (ORDER BY dt) e_date  FROM
     (
        select "Date" dt,"Value" value,
               LAG("Value") OVER (ORDER BY "Date") pvalue,
               LEAD("Value") OVER (ORDER BY "Date") nvalue
        from T
     ) T1
     WHERE pvalue is NULL or value<>pvalue or nvalue is NULL 
   )
WHERE E_DATE is NOT NULL
)
SELECT COUNT(*) FROM IntTable where value = 0 

SQLFiddle demo

2.Period Between every shut down

WITH IntTable AS
( SELECT * FROM
  (
   SELECT dt b_date,value,LEAD(dt) OVER (ORDER BY dt) e_date  FROM
     (
        select "Date" dt,"Value" value,
               LAG("Value") OVER (ORDER BY "Date") pvalue,
               LEAD("Value") OVER (ORDER BY "Date") nvalue
        from T
     ) T1
     WHERE pvalue is NULL or value<>pvalue or nvalue is NULL 
   )
WHERE E_DATE is NOT NULL
)
SELECT b_date,e_date, (e_date-b_date) * 60 * 24 FROM IntTable where value = 1 

SQLFiddle demo

Answer 2

Hi i have tried with below code it's displaying results as expected

with cte
    as
    (
    select Rownum rn,a.* from table a 
    )
    select date1 as start_time,endtime,  (endtime-date1)*24*60 as period 
    from 
    (
    select date1,value,case 
    when 
    value=1 then
    lead(date1) over (order by date1)
    else null
    end
     as endtime
    from
    (
    select date1,value from cte where cte.rn=1
    union all
    select a.date1,a.value from cte a
    join
    cte b
    on 
    a.rn=b.rn+1
    and( (a.value=1 and b.value=0) or (a.value=0 and b.value=1)) 
    ) order by date1) where value=1

Answer 3

Your question has two parts, and both needs to be handled in two different queries. As the output is based on two different sets of rows.

Setup

SQL> CREATE TABLE t AS SELECT * FROM(WITH DATA(dt, status) AS(
  2  SELECT to_date('07-Jul-15 12:05:00', 'dd-Mon-rr hh24:mi:ss', 'NLS_DATE_LANGUAGE=AMERICAN'), 1 FROM dual UNION ALL
  3  SELECT to_date('07-Jul-15 12:10:00', 'dd-Mon-rr hh24:mi:ss', 'NLS_DATE_LANGUAGE=AMERICAN'), 1  FROM dual UNION ALL
  4  SELECT to_date('07-Jul-15 12:15:00', 'dd-Mon-rr hh24:mi:ss', 'NLS_DATE_LANGUAGE=AMERICAN'), 1  FROM dual UNION ALL
  5  SELECT to_date('07-Jul-15 12:20:00', 'dd-Mon-rr hh24:mi:ss', 'NLS_DATE_LANGUAGE=AMERICAN'), 0  FROM dual UNION ALL
  6  SELECT to_date('07-Jul-15 12:25:00', 'dd-Mon-rr hh24:mi:ss', 'NLS_DATE_LANGUAGE=AMERICAN'), 0  FROM dual UNION ALL
  7  SELECT to_date('07-Jul-15 12:30:00', 'dd-Mon-rr hh24:mi:ss', 'NLS_DATE_LANGUAGE=AMERICAN'), 0  FROM dual UNION ALL
  8  SELECT to_date('07-Jul-15 12:35:00', 'dd-Mon-rr hh24:mi:ss', 'NLS_DATE_LANGUAGE=AMERICAN'), 1  FROM dual UNION ALL
  9  SELECT to_date('07-Jul-15 12:40:00', 'dd-Mon-rr hh24:mi:ss', 'NLS_DATE_LANGUAGE=AMERICAN'), 1  FROM dual UNION ALL
 10  SELECT to_date('07-Jul-15 12:45:00', 'dd-Mon-rr hh24:mi:ss', 'NLS_DATE_LANGUAGE=AMERICAN'), 1  FROM dual UNION ALL
 11  SELECT to_date('07-Jul-15 12:50:00', 'dd-Mon-rr hh24:mi:ss', 'NLS_DATE_LANGUAGE=AMERICAN'), 1  FROM dual UNION ALL
 12  SELECT to_date('07-Jul-15 12:55:00', 'dd-Mon-rr hh24:mi:ss', 'NLS_DATE_LANGUAGE=AMERICAN'), 0  FROM dual UNION ALL
 13  SELECT to_date('07-Jul-15 13:00:00', 'dd-Mon-rr hh24:mi:ss', 'NLS_DATE_LANGUAGE=AMERICAN'), 0  FROM dual UNION ALL
 14  SELECT to_date('07-Jul-15 13:05:00', 'dd-Mon-rr hh24:mi:ss', 'NLS_DATE_LANGUAGE=AMERICAN'), 1  FROM dual UNION ALL
 15  SELECT to_date('07-Jul-15 13:10:00', 'dd-Mon-rr hh24:mi:ss', 'NLS_DATE_LANGUAGE=AMERICAN'), 1  FROM dual UNION ALL
 16  SELECT to_date('07-Jul-15 13:15:00', 'dd-Mon-rr hh24:mi:ss', 'NLS_DATE_LANGUAGE=AMERICAN'), 1  FROM dual UNION ALL
 17  SELECT to_date('07-Jul-15 13:20:00', 'dd-Mon-rr hh24:mi:ss', 'NLS_DATE_LANGUAGE=AMERICAN'), 0  FROM dual UNION ALL
 18  SELECT to_date('07-Jul-15 13:25:00', 'dd-Mon-rr hh24:mi:ss', 'NLS_DATE_LANGUAGE=AMERICAN'), 0  FROM dual
 19  ) SELECT * FROM DATA);

Table created.

Table data

SQL> SELECT * FROM t;

DT                     STATUS
------------------ ----------
07-Jul-15 12:05:00          1
07-Jul-15 12:10:00          1
07-Jul-15 12:15:00          1
07-Jul-15 12:20:00          0
07-Jul-15 12:25:00          0
07-Jul-15 12:30:00          0
07-Jul-15 12:35:00          1
07-Jul-15 12:40:00          1
07-Jul-15 12:45:00          1
07-Jul-15 12:50:00          1
07-Jul-15 12:55:00          0
07-Jul-15 13:00:00          0
07-Jul-15 13:05:00          1
07-Jul-15 13:10:00          1
07-Jul-15 13:15:00          1
07-Jul-15 13:20:00          0
07-Jul-15 13:25:00          0

17 rows selected.

1. Number of shutdowns: The Number of shut down in this case is 3 based on 0 is ON and 1 is OFF.

You need to use LAG() analytic function.

SQL> SELECT TO_CHAR(dt, 'dd-Mon-rr hh24:mi:ss') dt,
  2    status
  3  FROM
  4    (SELECT t.*,
  5      CASE
  6        WHEN lag(status) OVER(ORDER BY dt) <> status
  7        THEN 1
  8        ELSE 0
  9      END chg
 10    FROM t
 11    )
 12  WHERE status = 0
 13  AND chg      =1;

DT                     STATUS
------------------ ----------
07-Jul-15 12:20:00          0
07-Jul-15 12:55:00          0
07-Jul-15 13:20:00          0

So, there are 3 rows in the output, which means 3 times the shutdown event occurred. To get the count, you just need to use the COUNT function.

2. Period Between every shut down

Example:

1. From: 07-Jul-15 12:05:00 To: 07-Jul-15 12:15:00 Duration : 15 Mins
2. From: 07-Jul-15 12:35:00 To: 07-Jul-15 12:50:00 Duration : 20 Mins

Once again, you need to use LAG() analytic function. Difference between dates returns number of days. To convert it into minutes, multiply it with 24*60.

SQL> SELECT * FROM(
  2  SELECT t.*,
  3      CASE
  4        WHEN lag(status) OVER(ORDER BY dt) <> status
  5        THEN 1
  6        ELSE 0
  7      END chg,
  8      24*60*(dt - lag(dt) over(order by dt)) gap
  9    FROM t
 10    ) t
 11  WHERE status =1 and chg =0;

DT                     STATUS        CHG        GAP
------------------ ---------- ---------- ----------
07-Jul-15 12:05:00          1          0
07-Jul-15 12:10:00          1          0          5
07-Jul-15 12:15:00          1          0          5
07-Jul-15 12:40:00          1          0          5
07-Jul-15 12:45:00          1          0          5
07-Jul-15 12:50:00          1          0          5
07-Jul-15 13:10:00          1          0          5
07-Jul-15 13:15:00          1          0          5

8 rows selected.

SQL>

So, based on above query, to find the total time when the system was up, use SUM.

SQL> SELECT SUM(gap) on_minutes FROM(
  2  SELECT t.*,
  3      CASE
  4        WHEN lag(status) OVER(ORDER BY dt) <> status
  5        THEN 1
  6        ELSE 0
  7      END chg,
  8      24*60*(dt - lag(dt) over(order by dt)) gap
  9    FROM t
 10    ) t
 11  WHERE status =1 and chg =0;

ON_MINUTES
----------
        35

SQL>

So, the system was up for 35 minutes.

Answer 4

You can test my answer on sqlfiddle: http://www.sqlfiddle.com/#!4/9c6a69/16

Test Data

create table test (dttm date, onoff number);

insert into test values (to_date('07-Jul-15 12:05:00', 'DD-MM-YY HH24:MI:SS'), 1 );
insert into test values (to_date('07-Jul-15 12:10:00', 'DD-MM-YY HH24:MI:SS'), 1 );
insert into test values (to_date('07-Jul-15 12:15:00', 'DD-MM-YY HH24:MI:SS'), 1 );
insert into test values (to_date('07-Jul-15 12:20:00', 'DD-MM-YY HH24:MI:SS'), 0 );
insert into test values (to_date('07-Jul-15 12:25:00', 'DD-MM-YY HH24:MI:SS'), 0 );
insert into test values (to_date('07-Jul-15 12:30:00', 'DD-MM-YY HH24:MI:SS'), 0 );
insert into test values (to_date('07-Jul-15 12:35:00', 'DD-MM-YY HH24:MI:SS'), 1 );
insert into test values (to_date('07-Jul-15 12:40:00', 'DD-MM-YY HH24:MI:SS'), 1 );
insert into test values (to_date('07-Jul-15 12:45:00', 'DD-MM-YY HH24:MI:SS'), 1 );
insert into test values (to_date('07-Jul-15 12:50:00', 'DD-MM-YY HH24:MI:SS'), 1 );
insert into test values (to_date('07-Jul-15 12:55:00', 'DD-MM-YY HH24:MI:SS'), 0 );
insert into test values (to_date('07-Jul-15 13:00:00', 'DD-MM-YY HH24:MI:SS'), 0 );
insert into test values (to_date('07-Jul-15 13:05:00', 'DD-MM-YY HH24:MI:SS'), 1 );
insert into test values (to_date('07-Jul-15 13:10:00', 'DD-MM-YY HH24:MI:SS'), 1 );
insert into test values (to_date('07-Jul-15 13:15:00', 'DD-MM-YY HH24:MI:SS'), 1 );
insert into test values (to_date('07-Jul-15 13:20:00', 'DD-MM-YY HH24:MI:SS'), 0 );
insert into test values (to_date('07-Jul-15 13:25:00', 'DD-MM-YY HH24:MI:SS'), 0 );

First of all, remove all unnecessary columns and keep only the on/off columns:

select t.dttm, t.onoff from test t
where not exists (select 'X' from test tt 
                  where tt.dttm =
                    (select max(ttt.dttm) from test ttt where ttt.dttm < t.dttm)
             and tt.onoff = t.onoff)

number of shutdowns:

with data as (
select t.dttm, t.onoff from test t
where not exists (select 'X' from test tt 
                 where tt.dttm =
                    (select max(ttt.dttm) from test ttt where ttt.dttm < t.dttm)
                 and tt.onoff = t.onoff)
)
select count(*) from data d where d.onoff=0;                                

ontime:

with data as (
select t.dttm, t.onoff from test t
where not exists (select 'X' from test tt 
                 where tt.dttm =
                    (select max(ttt.dttm) from test ttt where ttt.dttm < t.dttm)
                 and tt.onoff = t.onoff)
)
select d1.dttm as ontime, 
d0.dttm as offtime, 
(d0.dttm - d1.dttm) * 24 * 60 as duration 
from data d0, data d1 
where d1.onoff=1 
and d0.dttm = (select min(dd0.dttm) from data dd0 where dd0.dttm > d1.dttm);