Multiple UNION ALL views within a view returning incorrect records?

Question

Hi,
I have a view which selects from multiple views with UNION ALL joining them. If I just select from the larg UNION ALL query I return more records (correct amount) than If I create a view, and select from it.
e.g.
SELECT *
FROM vw_load_1
UNION ALL
SELECT *
FROM vw_load_2
UNION ALL
SELECT *
FROM vw_load_3
UNION ALL
SELECT *
FROM vw_load_4
UNION ALL
SELECT *
FROM vw_load_5
Returns 405 Records
but
CREATE VIEW vw_master_load
AS
SELECT *
FROM vw_load_1
UNION ALL
SELECT *
FROM vw_load_2
UNION ALL
SELECT *
FROM vw_load_3
UNION ALL
SELECT *
FROM vw_load_4
UNION ALL
SELECT *
FROM vw_load_5;
SELECT COUNT(*)
FROM vw_master_load
Returns 307 records
Can anyone explain why, or how to get around this?
Oracle version: Oracle Database 11g Enterprise Edition Release 11.2.0.2.0 - 64bit Production
PL/SQL Release 11.2.0.2.0 - Production

Answer 1

Hi,
Are you saying that you run:
select count(*) from (
  SELECT *
  FROM vw_load_1
  UNION ALL
  SELECT *
  FROM vw_load_2
  UNION ALL
  SELECT *
  FROM vw_load_3
  UNION ALL
  SELECT *
  FROM vw_load_4
  UNION ALL
  SELECT *
  FROM vw_load_5
result is: 307 And then you run
  SELECT *
  FROM vw_load_1
  UNION ALL
  SELECT *
  FROM vw_load_2
  UNION ALL
  SELECT *
  FROM vw_load_3
  UNION ALL
  SELECT *
  FROM vw_load_4
  UNION ALL
  SELECT *
  FROM vw_load_5
returns 405 rowsIf so, that is very strange.
Can you an example we can re-produce?
Regards,
Peter