Tabibitosan method tutorial by Aketi Jyuuzou

user503699

Aketi Jyuuzou wrote:
**************************
For exsample3 (collect Rows continued Months)

create table Ex3 (DateVal primary key) as
select date '2009-09-01' from dual union
select date '2009-10-01' from dual union
select date '2009-12-01' from dual union
select date '2010-01-01' from dual union
select date '2010-02-01' from dual union
select date '2010-04-01' from dual;

select min(DateVal),max(DateVal),count(*)
from (select DateVal,
extract(year  from DateVal)*12
+extract(month from DateVal)
-Row_Number() over(order by DateVal)
as disTance
from Ex3)
group by disTance
order by min(DateVal);

MIN(DATE MAX(DATE   COUNT(*)
-------- -------- ----------
09-09-01 09-10-01          2
09-12-01 10-02-01          3
10-04-01 10-04-01          1

Aketi,

First of all, thanks a lot for this great thread. It is in my top bookmarks.
In above example, you have showed how this technique can be applied to group the rows with difference of a month.
I was wondering if this technique can be applied to group rows within a specific interval.
For e.g. is it possible to group the rows in the following resultset, within interval of 1 minute?

30-JULY-2010 05:10:00
30-JULY-2010 05:50:00
30-JULY-2010 06:55:00
30-JULY-2010 07:54:00
30-JULY-2010 08:58:00

The above data should be grouped as follows (group number is only an indicator and need not be continuous)

30-JULY-2010 05:10:00      1
30-JULY-2010 05:50:00      1
30-JULY-2010 06:55:00      2
30-JULY-2010 07:54:00      2
30-JULY-2010 08:58:00      3

Can you please help?

Aketi Jyuuzou

Nice question :-)
But this problem needs rival solution of "Tabibitosan method"
Like this thread 956106

with t(Val) as(
select to_date('20100630 05:10:00','yyyymmdd hh24:mi:ss') from dual union
select to_date('20100630 05:50:00','yyyymmdd hh24:mi:ss') from dual union
select to_date('20100630 06:55:00','yyyymmdd hh24:mi:ss') from dual union
select to_date('20100630 07:54:00','yyyymmdd hh24:mi:ss') from dual union
select to_date('20100630 08:58:00','yyyymmdd hh24:mi:ss') from dual)
select to_char(Val,'yyyymmdd hh24:mi:ss') as Val,
sum(willSum) over(order by Val) as GID
from (select Val,
      case when Lag(Val) over(order by Val) + InterVal '1' hour > Val
           then 0 else 1 end as willSum
        from t)
order by Val;

VAL                GID
-----------------  ---
20100630 05:10:00    1
20100630 05:50:00    1
20100630 06:55:00    2
20100630 07:54:00    2
20100630 08:58:00    3

user503699

Aketi Jyuuzou wrote:
Nice question :-)
But this problem needs rival solution of "Tabibitosan method"
Like this thread 956106

Aketi,
Many Thanks.
My sincere apologies as I realised that my description of the problem and test data (in earlier post) were not consistent with each other.
Please allow me to rephrase my question.
With the following data, I would like to group the records within one minute interval and get the first record within the group.
Here is the test case

SQL> create table t1 (x date, y int, id int) ;

Table created.

SQL> insert into t1 values (to_date('10/06/2008 03:34:40 PM', 'MM/DD/YYYY HH12:MI:SS AM'), 10, 228)
  2  /

1 row created.

SQL> insert into t1 values (to_date('10/06/2008 03:34:30 PM', 'MM/DD/YYYY HH12:MI:SS AM'), 10, 228)
  2  /

1 row created.

SQL> insert into t1 values (to_date('10/06/2008 03:34:50 PM', 'MM/DD/YYYY HH12:MI:SS AM'), 10, 228)
  2  /

1 row created.

SQL> insert into t1 values (to_date('10/06/2008 04:28:30 PM', 'MM/DD/YYYY HH12:MI:SS AM'), 10, 228)
  2  /

1 row created.

SQL> insert into t1 values (to_date('10/06/2008 04:29:30 PM', 'MM/DD/YYYY HH12:MI:SS AM'), 10, 228)
  2  /

1 row created.

SQL> insert into t1 values (to_date('10/06/2008 04:30:30 PM', 'MM/DD/YYYY HH12:MI:SS AM'), 10, 228)
  2  /

1 row created.

SQL> insert into t1 values (to_date('10/06/2008 04:30:29 PM', 'MM/DD/YYYY HH12:MI:SS AM'), 10, 228)
  2  /

1 row created.

SQL> insert into t1 values (to_date('10/06/2008 04:27:35 PM', 'MM/DD/YYYY HH12:MI:SS AM'), 12, 228)
  2  /

1 row created.

SQL> insert into t1 values (to_date('10/06/2008 03:33:34 PM', 'MM/DD/YYYY HH12:MI:SS AM'), 21, 228)
  2  /

1 row created.

SQL> insert into t1 values (to_date('10/06/2008 03:34:15 PM', 'MM/DD/YYYY HH12:MI:SS AM'), 10, 228)
  2  /

1 row created.

SQL> insert into t1 values (to_date('10/07/2008 12:59:40 PM', 'MM/DD/YYYY HH12:MI:SS AM'), 10, 229)
  2  /

1 row created.

SQL> insert into t1 values (to_date('10/07/2008 12:59:50 PM', 'MM/DD/YYYY HH12:MI:SS AM'), 10, 229)
  2  /

1 row created.

SQL> insert into t1 values (to_date('10/07/2008 01:00:05 PM', 'MM/DD/YYYY HH12:MI:SS AM'), 10, 229)
  2  /

1 row created.

SQL> insert into t1 values (to_date('10/07/2008 01:00:30 PM', 'MM/DD/YYYY HH12:MI:SS AM'), 10, 229)
  2  /

1 row created.

SQL> insert into t1 values (to_date('10/07/2008 01:00:49 PM', 'MM/DD/YYYY HH12:MI:SS AM'), 10, 229)
  2  /

1 row created.

SQL> insert into t1 values (to_date('10/07/2008 01:00:55 PM', 'MM/DD/YYYY HH12:MI:SS AM'), 10, 229)
  2  /

1 row created.

SQL> commit ;

Commit complete.

SQL> select id, x, y, row_number() over (partition by id order by x) rn from t1 order by id, x
  2  /

        ID X                             Y         RN
---------- -------------------- ---------- ----------
       228 06-OCT-2008 15:33:34         21          1
       228 06-OCT-2008 15:34:15         10          2
       228 06-OCT-2008 15:34:30         10          3
       228 06-OCT-2008 15:34:40         10          4
       228 06-OCT-2008 15:34:50         10          5
       228 06-OCT-2008 16:27:35         12          6
       228 06-OCT-2008 16:28:30         10          7
       228 06-OCT-2008 16:29:30         10          8
       228 06-OCT-2008 16:30:29         10          9
       228 06-OCT-2008 16:30:30         10         10
       229 07-OCT-2008 12:59:40         10          1
       229 07-OCT-2008 12:59:50         10          2
       229 07-OCT-2008 13:00:05         10          3
       229 07-OCT-2008 13:00:30         10          4
       229 07-OCT-2008 13:00:49         10          5
       229 07-OCT-2008 13:00:55         10          6

16 rows selected.

Expected output

        ID              X                      Y
---------- --------------------  ----------
       228 06-OCT-2008 15:33:34         21
       228 06-OCT-2008 15:34:40         10
       228 06-OCT-2008 16:27:35         12
       228 06-OCT-2008 16:29:30         10
       228 06-OCT-2008 16:30:30         10
       229 07-OCT-2008 12:59:40         10
       229 07-OCT-2008 13:00:49         10

Aketi Jyuuzou

About 2 years before,I solved it
703724

with t(Val) as(
select to_date('10/06/2008 03:34:40', 'MM/DD/YYYY HH24:MI:SS') from dual union
select to_date('10/06/2008 03:34:30', 'MM/DD/YYYY HH24:MI:SS') from dual union
select to_date('10/06/2008 03:34:50', 'MM/DD/YYYY HH24:MI:SS') from dual union
select to_date('10/06/2008 04:28:30', 'MM/DD/YYYY HH24:MI:SS') from dual union
select to_date('10/06/2008 04:29:30', 'MM/DD/YYYY HH24:MI:SS') from dual union
select to_date('10/06/2008 04:30:30', 'MM/DD/YYYY HH24:MI:SS') from dual union
select to_date('10/06/2008 04:30:29', 'MM/DD/YYYY HH24:MI:SS') from dual union
select to_date('10/06/2008 04:27:35', 'MM/DD/YYYY HH24:MI:SS') from dual union
select to_date('10/06/2008 03:33:34', 'MM/DD/YYYY HH24:MI:SS') from dual union
select to_date('10/06/2008 03:34:15', 'MM/DD/YYYY HH24:MI:SS') from dual union
select to_date('10/07/2008 12:59:40', 'MM/DD/YYYY HH24:MI:SS') from dual union
select to_date('10/07/2008 12:59:50', 'MM/DD/YYYY HH24:MI:SS') from dual union
select to_date('10/07/2008 13:00:05', 'MM/DD/YYYY HH24:MI:SS') from dual union
select to_date('10/07/2008 13:00:30', 'MM/DD/YYYY HH24:MI:SS') from dual union
select to_date('10/07/2008 13:00:49', 'MM/DD/YYYY HH24:MI:SS') from dual union
select to_date('10/07/2008 13:00:55', 'MM/DD/YYYY HH24:MI:SS') from dual)
select to_char(Val,'yyyy-mm-dd hh24:mi:ss') as Val
from (select Val,min(Val) over() as startVal,
      min(Val) over(order by Val
                    range between InterVal '1' minute following
                              and unbounded following) as nextVal
      from t)
start with Val = startVal
connect by prior nextVal = Val;

VAL
-------------------
2008-10-06 03:33:34
2008-10-06 03:34:40
2008-10-06 04:27:35
2008-10-06 04:29:30
2008-10-06 04:30:30
2008-10-07 12:59:40
2008-10-07 13:00:49

user503699

Aketi Jyuuzou wrote:
About 2 years before,I solved it
703724

Aketi,

Many thanks for your response.
Is this the only way (using SQL) to solve this problem?
The main reason for asking for alternative solution is this solution requires accessing and sorting the table twice.

SQL> select * from table(dbms_xplan.display_cursor) ;

PLAN_TABLE_OUTPUT
----------------------------------------------------------------------------------------------------
SQL_ID  9skznz4u401t1, child number 0
-------------------------------------
select id,x,y from (select id,x,y,min(x) over (partition by id) startx,
min(x) over (partition by id order by x range between interval '1' minute
following and unbounded following) nextval from t1) start with x = startx
connect by prior nextval = x

Plan hash value: 775368986

----------------------------------------------------------------------------------
| Id  | Operation                 | Name | Rows  | Bytes | Cost (%CPU)| Time     |
----------------------------------------------------------------------------------
|   0 | SELECT STATEMENT          |      |       |       |     4 (100)|          |
|*  1 |  CONNECT BY WITH FILTERING|      |       |       |            |          |
|*  2 |   VIEW                    |      |    16 |  1136 |     4  (25)| 00:00:01 |
|   3 |    WINDOW SORT            |      |    16 |   240 |     4  (25)| 00:00:01 |
|   4 |     TABLE ACCESS FULL     | T1   |    16 |   240 |     3   (0)| 00:00:01 |
|*  5 |   HASH JOIN               |      |       |       |            |          |
|   6 |    CONNECT BY PUMP        |      |       |       |            |          |
|   7 |    VIEW                   |      |    16 |   704 |     4  (25)| 00:00:01 |
|   8 |     WINDOW SORT           |      |    16 |   240 |     4  (25)| 00:00:01 |
|   9 |      TABLE ACCESS FULL    | T1   |    16 |   240 |     3   (0)| 00:00:01 |
----------------------------------------------------------------------------------

Predicate Information (identified by operation id):
---------------------------------------------------

   1 - access("X"=PRIOR NULL)
   2 - filter("X"="STARTX")
   5 - access("X"=PRIOR NULL)

p.s. Please don't suggest MODEL clause

Edited by: user503699 on Aug 2, 2010 6:52 PM

Aketi Jyuuzou

user503699 wrote:
Is this the only way (using SQL) to solve this problem?
The main reason for asking for alternative solution is this solution requires accessing and sorting the table twice.

Ummm

I think that there are 2 solutions.
One is recursive with clause insted of above HierarchicalQuery.
And The other is PipeLineTableFunction.

783956

Hi Alan,

>
I am a little dense,...
>

No, you're not... I had to think about it too

Indeed, it is very slick. A known monotonous sequence (the row numbers) applied to a sparse sequence of monotonous values (the other sequence) reveals the sparse groups in the sequence because their difference is constant in each group.

Very nice and elegant!

Thank you Aketi !!

John.