Feature #2058 - Window Function: frame exclude clause

[asfernandes]

No description provided.

[sim1984]

This is a topic for another PR, but I would like to point out that to fully complete the window theme, it is necessary to add frames with GROUPS units.

<window frame> ::=
  {RANGE | ROWS | GROUPS} <window frame extent> [<window frame exclusion>]

select hire_date
    -- include current & three previous rows
  , count(*) over ( order by hire_date rows 3 preceding ) prev3_rows
    -- include all rows between hire_date - 3 and hire_date for the current row
  , count(*) over ( order by hire_date range 3 preceding ) prev3_days
    -- include all rows with the any of the previous three and current hire_dates
  , count(*) over ( order by hire_date groups 3 preceding ) prev3_values
from   hr.employees
where  hire_date >= date'2015-03-03'
fetch first 5 rows only;

HIRE_DATE   PREV3_ROWS PREV3_DAYS PREV3_VALUES
----------- ---------- ---------- ------------
03-MAR-2015          1          1            1
10-MAR-2015          2          2            3
10-MAR-2015          3          2            3
11-MAR-2015          4          3            4
19-MAR-2015          4          1            5