Crear tabla con fechas ANSI SQL y Vertica

Con ANSI SQL:

WITH 
n AS ( /* numeracion del 0 al 9 */
    select 0 as i union all  
    select 1 union all
    select 2 union all 
    select 3 union all 
    select 4 union all 
    select 5 union all 
    select 6 union all 
    select 7 union all 
    select 8 union all 
    select 9
)
,numbers AS ( /* multiplicacion carteciana de n numeros */
     SELECT 
          a.i -- n = 10
          * 10 + b.i -- n x 10n = 100
          * 100 + c.i -- n x 10n x 100n = 1000
          AS i
      FROM n AS a
      CROSS JOIN n AS b
      CROSS JOIN n AS c
)
,fechas AS ( /* numeros a fecha con un valor inicial */
    SELECT 
        DATE('0001-01-01') + i AS fecha
    FROM numbers
)
SELECT * FROM fechas
ORDER BY fecha

Con Vertica

WITH 
inicio AS (
    SELECT '2019-01-15'::TIMESTAMP as tm 
    UNION ALL 
    SELECT '2021-12-15'::TIMESTAMP
)
,fechas AS (
    SELECT 
        date(ts) AS fecha 
    FROM inicio 
    TIMESERIES ts AS '1 day' OVER( ORDER BY tm )
)
SELECT * FROM fechas