1Jonathan LewisUKOUG Dec 2000

Analytic Functions

Agenda

Who am I

Historical Problems

The Future

Questions (and answers)

2Jonathan LewisUKOUG Dec 2000

Analytic Functions

Who am I ?

Independent Consultant.

Design, Strategy, Briefing, Training

Reviews and Trouble-shooting

http://www.jlcomp.demon.co.uk

3Jonathan LewisUKOUG Dec 2000

Analytic Functions

History

For each store

report the two top sellers

4Jonathan LewisUKOUG Dec 2000

Analytic Functions

History

create table game_sale (

title varchar2(20),

store varchar2(10),

sales number(10,2)

);

5Jonathan LewisUKOUG Dec 2000

Analytic Functions

History

('Portal Combat', 'London', 1824);

('Manic the Gerbil', 'London', 52);

('Age of Umpires', 'London', 110);

('Crash Simulator', 'London', 247);

('Dome', 'London', 2167);

6Jonathan LewisUKOUG Dec 2000

Analytic Functions

History

select

store, title, sales

from

game_sale

order by

store,

sales desc

7Jonathan LewisUKOUG Dec 2000

Analytic Functions

History

Glasgow Crash Simulator 1934 Manic the Gerbil 913 Dome 482 Portal Combat 315 Age of Umpires 72

London Dome 2167 Portal Combat 1824 Crash Simulator 247 Age of Umpires 110 Manic the Gerbil 52

8Jonathan LewisUKOUG Dec 2000

Analytic Functions

History

declarecursor c1 is

select store, title, salesfrom game_saleorder by store, sales desc

;m_last_row c1%rowtype;m_out_ct number := 0;

begindo something . . .

end;

9Jonathan LewisUKOUG Dec 2000

Analytic Functions

History

for r1 in c1 loopif (m_last_row.store != r1.store) then m_out_ct := 0; dbms_output.new_line;end if;

if m_out_ct != 2 then dbms_output.put_line (

r1.store || ' - ' || r1.title || ' - ' || r1.sales

); m_out_ct := m_out_ct + 1;end if;

m_last_row := r1;end loop;

10Jonathan LewisUKOUG Dec 2000

Analytic Functions

History

Glasgow - Crash Simulator - 1934

Glasgow - Manic the Gerbil - 913

London - Dome - 2167

London - Portal Combat - 1824

11Jonathan LewisUKOUG Dec 2000

Analytic Functions

History

('Portal Combat', 'London', 1824);

('Manic the Gerbil', 'London', 52);

('Age of Umpires', 'London', 110);

('Crash Simulator', 'London', 1824);

('Dome', 'London', 2167);

12Jonathan LewisUKOUG Dec 2000

Analytic Functions

History

select store, title, salesfrom game_sale gs1where 2 > (

select count(*)from game_sale gs2where gs2.store = gs1.storeand gs2.sales > gs1.sales)

order bystore, sales desc;

13Jonathan LewisUKOUG Dec 2000

Analytic Functions

History

STORE TITLE SALES

---------- -------------------- ---------

Glasgow Crash Simulator 1934

Manic the Gerbil 913

London Dome 2167

Portal Combat 1824

14Jonathan LewisUKOUG Dec 2000

Analytic Functions

History

('Portal Combat', 'London', 1824);

('Manic the Gerbil', 'London', 52);

('Age of Umpires', 'London', 110);

('Crash Simulator', 'London', 1824);

('Dome', 'London', 2167);

where 2 > (select count(*)

15Jonathan LewisUKOUG Dec 2000

Analytic Functions

The Future.

select

store, title, sales,

rank() over (

partition by store

order by sales desc

) as in_store_rank

from

game_sale

;

16Jonathan LewisUKOUG Dec 2000

Analytic Functions

The Future

Glasgow Crash Simulator 1934 1

Manic the Gerbil 913 2

Dome 482 3

Portal Combat 315 4

Age of Umpires 72 5

London Dome 2167 1

Portal Combat 1824 2

Crash Simulator 247 3

Age of Umpires 110 4

Manic the Gerbil 52 5

17Jonathan LewisUKOUG Dec 2000

Analytic Functions

The Future

select store, title, salesfrom (select store, title, sales,

rank() over (partition by storeorder by sales desc

) as in_store_rankfrom

game_sale)

where in_store_rank <= 2order by store, in_store_rank;

18Jonathan LewisUKOUG Dec 2000

Analytic Functions

The Future

STORE TITLE SALES

---------- -------------------- ---------

Glasgow Crash Simulator 1934

Tonic the Gerbil 913

London Dome 2167

Portal Combat 1824

19Jonathan LewisUKOUG Dec 2000

Analytic Functions

The Future

select store, title, salesfrom (select store, title, sales,

rank() over (partition by storeorder by sales desc

) as in_store_rank,sum(sales) over (

partition by store) as store_totals

from game_sale)where in_store_rank <= 2order bystore_totals desc, in_store_rank;

20Jonathan LewisUKOUG Dec 2000

Analytic Functions

The Future

STORE TITLE SALES

---------- -------------------- ---------

London Dome 2167

Portal Combat 1824

Glasgow Crash Simulator 1934

Tonic the Gerbil 913

21Jonathan LewisUKOUG Dec 2000

Analytic Functions

The Future

AVG SUM** COUNT

MAX MIN

RANK** ROW_NUMBER

DENSE_RANK PERCENT_RANK

22Jonathan LewisUKOUG Dec 2000

Analytic Functions

The Future

RATIO_TO_REPORT

LEAD LAG

FIRST_VALUE LAST_VALUE

NTILE CUME_DIST

23Jonathan LewisUKOUG Dec 2000

Analytic Functions

The Future

VARIANCE STDDEV CORR

VAR_POP VAR_SAMP

COVAR_POP COVAR_SAMP

STDDEV_POP STDDEV_SAMP

REGR_ (linear regression function)

24Jonathan LewisUKOUG Dec 2000

Analytic Functions

The Future

Title Sales Previous Delta

---------------- ------- --------- ------

Crash Simulator 1934 913 1021

Tonic the Gerbil 913 482 431

Dome 482 315 167

Portal Combat 315 72 243

Age of Umpires 72

25Jonathan LewisUKOUG Dec 2000

Analytic Functions

The Future

select title, sales, previous,

this_sale - next_sale delta

from (

select title, sales,

lead(sales,1) over (

partition by store

order by sales desc

) as previous

from

game_sale

);

26Jonathan LewisUKOUG Dec 2000

Analytic Functions

The Future

Store Title Sale St % Co %-------- ----------------- ---- ---- -----Glasgow Crash Simulator 1934 .52 .24 Tonic the Gerbil 913 .25 .11 Dome 482 .13 .06 Portal Combat 315 .08 .04 Age of Umpires 72 .02 .01

London Dome 2167 .49 .27 Portal Combat 1824 .41 .22 Crash Simulator 247 .06 .03 Age of Umpires 110 .03 .01 Tonic the Gerbil 52 .01 .01

27Jonathan LewisUKOUG Dec 2000

Analytic Functions

The Future

select store, title, sales,

ratio_to_report(sales) over (

partition by store

) store_ratio,

ratio_to_report(sales) over (

) country_ratio

from game_sale

order by

store, sales desc;

28Jonathan LewisUKOUG Dec 2000

Analytic Functions

The Future

Store Week Ending Sales Rolling

-------- ----------- ----- -------

Glasgow 07-May-2000 4,000 5,000.0

14-May-2000 5,000 5,500.0

21-May-2000 6,000 6,000.0

28-May-2000 7,000 6,760.4

04-Jun-2000 8,000 7,287.6

11-Jun-2000 7,802 7,714.4

18-Jun-2000 7,636 7,877.4

25-Jun-2000 8,134 7,882.0

2-Jul-2000 7,815 7,902.0

9-Jul-2000 8,023 7,990.7

29Jonathan LewisUKOUG Dec 2000

Analytic Functions

The Future

select

store, week_ending, sales,

avg(sales) over(

partition by store

order by week_ending

range between

14 preceding and 14 following

) rolling_5

from

sales_history

order by

store, week_ending;

30Jonathan LewisUKOUG Dec 2000

Analytic Functions

The Future

Store Week Ending Sales Running

-------- ----------- ----- -------

Glasgow 07-May-2000 4,000 4,000

14-May-2000 5,000 9,500

21-May-2000 6,000 15,000

28-May-2000 7,000 22,000

04-Jun-2000 8,000 30,000

11-Jun-2000 7,802 37,802

18-Jun-2000 7,636 45,438

25-Jun-2000 8,134 53,572

2-Jul-2000 7,815 61,387

9-Jul-2000 8,023 69,410

31Jonathan LewisUKOUG Dec 2000

Analytic Functions

The Future

select

store, week_ending, sales,

avg(sales) over(

partition by store

order by week_ending

range unbounded preceding

) running

from

sales_history

order by

store, week_ending;

32Jonathan LewisUKOUG Dec 2000

Analytic Functions

Warnings

• Lots of sorting.

• Use only on small result sets

• pl/sql doesn’t understand it

• can’t often use view effectively

33Jonathan LewisUKOUG Dec 2000

Analytic Functions

Conclusion

• Enormously powerful

• Use in-line views to make it easy