Insert as per sort by statement given

Question

In below given example, the data does not get inserted as per the sorting given i.e ORDER BY c002,c003
Kindly suggest the solution..
Sanjay
BEGIN
MERGE INTO my_table a
  USING (
     SELECT seq_id,
          c001, -- Holding primary key
          c002,
          c003,
          c004,
          c005
     FROM apex_collections
     WHERE collection_name = 'MY_COLLECTION'  ORDER BY c002,c003
     ) b
    ON (a.tbl_col1 = b.c001)
  WHEN NOT MATCHED THEN
    INSERT (a.tbl_col2, a.tbl_col3, a.tbl_col4, a.tbl_col5)
    VALUES (b.c002, b.c003, b.c004, b.c005);
END;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           

Answer 1

user12957777 wrote:
In below given example, the data does not get inserted as per the sorting given i.e ORDER BY c002,c003
Kindly suggest the solution..
Sanjay
BEGIN
MERGE INTO my_table a
USING (
     SELECT seq_id,
          c001, -- Holding primary key
          c002,
          c003,
          c004,
          c005
     FROM apex_collections
     WHERE collection_name = 'MY_COLLECTION'  ORDER BY c002,c003
     ) b
ON (a.tbl_col1 = b.c001)
WHEN NOT MATCHED THEN
INSERT (a.tbl_col2, a.tbl_col3, a.tbl_col4, a.tbl_col5)
VALUES (b.c002, b.c003, b.c004, b.c005);
END;The USING clause provides a set of data to the MERGE statement. Just because you order that set of data inside the USING clause doesn't mean that it causes the MERGE statement to insert data in that order.
Your ordered set of data (b) is being joined to your merging table my_table, to determine what matches and what doesn't. At that point the ordering is irrelevant, because the optimizer will join the data for the merge statement in the best way it can.
As others have said, it doesn't matter what order your data is inserted.