Crearía solo una consulta:
DELETE FROM mytable
WHERE company in (
SELECT Company
FROM (
SELECT Company,
COUNT(CASE WHEN value IS NULL THEN 1 END)
OVER (PARTITION BY company ORDER BY id
ROWS BETWEEN CURRENT ROW AND 2 FOLLOWING) As cnt,
COUNT(CASE WHEN value IS NULL THEN 1 END)
OVER (PARTITION BY company)
/
COUNT(*)
OVER (PARTITION BY company) As p50
) alias
WHERE cnt >= 3 OR p50 > 0.5
)
Un índice compuesto en las columnas (empresa + valor) puede ayudar a obtener la máxima velocidad de esta consulta.
EDITAR
La consulta anterior no funciona
La he corregido un poco, aquí hay una demostración:http://sqlfiddle.com/#!15/c9bfe/7
Se han cambiado dos cosas:
- PARTICIÓN POR empresa ORDEN POR fecha en lugar de ORDENAR POR id
- conversión explícita a numérico (porque los enteros se han truncado a 0):
OVER (PARTICIÓN POR empresa)::numeric
SELECT company, cnt, p50
FROM (
SELECT company,
COUNT(CASE WHEN value IS NULL THEN 1 END)
OVER (PARTITION BY company ORDER BY date
ROWS BETWEEN CURRENT ROW AND 2 FOLLOWING) As cnt,
SUM(CASE WHEN value IS NULL THEN 1 ELSE 0 END)
OVER (PARTITION BY company)::numeric
/
COUNT(*)
OVER (PARTITION BY company) As p50
FROM mytable
) alias
-- WHERE cnt >= 3 OR p50 > 0.5
y ahora la consulta de eliminación debería funcionar:
DELETE FROM mytable
WHERE company in (
SELECT company
FROM (
SELECT company,
COUNT(CASE WHEN value IS NULL THEN 1 END)
OVER (PARTITION BY company ORDER BY date
ROWS BETWEEN CURRENT ROW AND 2 FOLLOWING) As cnt,
SUM(CASE WHEN value IS NULL THEN 1 ELSE 0 END)
OVER (PARTITION BY company)::numeric
/
COUNT(*)
OVER (PARTITION BY company) As p50
FROM mytable
) alias
WHERE cnt >= 3 OR p50 > 0.5
)
