Alternative to UNION SQL Oracle 11g

Question

Hi,
is any possibility to replace this SQL statement with another one?
Be aware that this one works and the tables are not identical.
String statement =" SELECT id, "+
     " sender_id, "+
     " date_created "+
     " FROM DOCUMENT_ARCHIVE da "+
     " where da.SOURCE_FILE_NAME = 'shpaig0140_shpsts_shpaig_C2KRMP1.txt' "+
     " union all "+
     " select file_id,"+
     " sender_id,"+
     " date_created "+
     " from DOCUMENT_FILE df "+
     " WHERE df.SOURCE_FILE_NAME = 'shpaig0140_shpsts_shpaig_C2KRMP1.txt' ";

Answer 1

Why do you feel the need to replace it if it gives correct results? If you need to union, then you need to union. Most other structures would not give identical results, that is, one row for each occurrence in each table.
About the only change that you could make would be to create a view along the lines of:
CREATE VIEW combined AS
SELECT id, sender_id, date_created, source_file_name
FROM document_archive
UNION ALL
SELECT id, sender_id, date_created, source_file_name
FROM document_fileThen query the view like:
SELECT id, sender_id, date_created
FROM combined
WHERE source_file_name = 'shpaig0140_shpsts_shpaig_C2KRMP1.txt' As a side note, I hope that your real code uses bind variables instead of string literals.
John