Re: Row pattern recognition

[Vik Fearing]

On 6/28/23 14:17, Tatsuo Ishii wrote:
Small question.
This query (with all the defaults made explicit):

SELECT s.company, s.tdate, s.price,
        FIRST_VALUE(s.tdate) OVER w,
        LAST_VALUE(s.tdate) OVER w,
        lowest OVER w
FROM stock AS s
WINDOW w AS (
   PARTITION BY s.company
   ORDER BY s.tdate
   ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
   EXCLUDE NO OTHERS
   MEASURES
     LAST(DOWN) AS lowest
   AFTER MATCH SKIP PAST LAST ROW
   INITIAL PATTERN (START DOWN+ UP+)
   DEFINE
     START AS TRUE,
     UP AS price > PREV(price),
     DOWN AS price < PREV(price)
);

     LAST(DOWN) AS lowest

should be "LAST(DOWN.price) AS lowest"?

Yes, it should be.  And the tdate='07-08-2023' row in the first 
resultset should have '07-08-2023' and '07-10-2023' as its 4th and 5th 
columns.

Since my brain is doing the processing instead of postgres, I made some 
human errors. :-)
--
Vik Fearing