Partition view on 10g and 11g

Question

Hi All,
I am on 10.2 Standard edition and 11.1 Standard edition (2 databases in the application, one on 10g, another on 11g).
Being on standard edition, cannot use many common features e.g. partitioning, bitmap indexes etc.
I use to think that, partitioned view are no more supported by Oracle. But I can see that it works. I created 3 tables TEMP1, TEMP2 and TEMP3, all with exact same structure (columns and indices). Then created a view TEMP_VIEW, which is like
select col1, col2, col3 .... from temp1
union all
select col1, col2, col3 .... from temp2
union all
select col1, col2, col3 .... from temp3Here are the query execution and plans
/* ----------------- 10g execution plan ----------------------- */
SQL> select * from temp_view where object_id=2620 and branch_cd = 'XYZ';
OWNER                          OBJECT_NAME                    SUBOBJECT_NAME                  OBJECT_ID DATA_OBJECT_ID
OBJECT_TYPE         CREATED   LAST_DDL_ TIMESTAMP           STATUS  T G S BRANC
SYS                            LOADER_TRIGGER_INFO                                                 2620
VIEW                18-FEB-09 16-APR-09 2009-02-18:10:07:57 VALID   N N N XYZ
Elapsed: 00:00:00.29
Execution Plan
   0      SELECT STATEMENT Optimizer=ALL_ROWS (Cost=2 Card=1 Bytes=132)
   1    0   VIEW OF 'TEMP_VIEW' (VIEW) (Cost=2 Card=1 Bytes=132)
   2    1     UNION-ALL (PARTITION)
   3    2       TABLE ACCESS (BY INDEX ROWID) OF 'TEMP1' (TABLE) (Cost=2 Card=1 Bytes=132)
   4    3         INDEX (UNIQUE SCAN) OF 'TEMP1_PK' (INDEX (UNIQUE)) (Cost=1 Card=1)
   5    2       TABLE ACCESS (BY INDEX ROWID) OF 'TEMP2' (TABLE) (Cost=2 Card=1 Bytes=132)
   6    5         INDEX (UNIQUE SCAN) OF 'TEMP2_PK' (INDEX (UNIQUE)) (Cost=1 Card=1)
   7    2       TABLE ACCESS (BY INDEX ROWID) OF 'TEMP3' (TABLE) (Cost=2 Card=1 Bytes=132)
   8    7         INDEX (UNIQUE SCAN) OF 'TEMP3_PK' (INDEX (UNIQUE)) (Cost=1 Card=1)
/* ----------------- 11g execution plan ----------------------- */
SQL> select * from temp_view where object_id=2620 and branch_cd = 'XYZ';
OWNER                          OBJECT_NAME                    SUBOBJECT_NAME                  OBJECT_ID DATA_OBJECT_ID
OBJECT_TYPE         CREATED   LAST_DDL_ TIMESTAMP           STATUS  T G S BRANC
PUBLIC                         GV$XML_AUDIT_TRAIL                                                  2620
SYNONYM             16-NOV-09 16-NOV-09 2009-11-16:16:36:08 VALID   N N N XYZ
Elapsed: 00:00:00.03
Execution Plan
   0      SELECT STATEMENT Optimizer=ALL_ROWS (Cost=6 Card=3 Bytes=396)
   1    0   VIEW OF 'TEMP_VIEW' (VIEW) (Cost=6 Card=3 Bytes=396)
   2    1     UNION-ALL
   3    2       TABLE ACCESS (BY INDEX ROWID) OF 'TEMP1' (TABLE) (Cost=2 Card=1 Bytes=102)
   4    3         INDEX (UNIQUE SCAN) OF 'TEMP1_PK' (INDEX (UNIQUE)) (Cost=1 Card=1)
   5    2       TABLE ACCESS (BY INDEX ROWID) OF 'TEMP2' (TABLE) (Cost=2 Card=1 Bytes=102)
   6    5         INDEX (UNIQUE SCAN) OF 'TEMP2_PK' (INDEX (UNIQUE)) (Cost=1 Card=1)
   7    2       TABLE ACCESS (BY INDEX ROWID) OF 'TEMP3' (TABLE) (Cost=2 Card=1 Bytes=102)
   8    7         INDEX (UNIQUE SCAN) OF 'TEMP3_PK' (INDEX (UNIQUE)) (Cost=1 Card=1)Questions
1) I am expecting same behaviour on Oracle enterprise edition, will that be the case ?
2) On 10g, execution plan shows "UNION-ALL (PARTITION)", but on 11g it says, "UNION-ALL". What does that imply?
3) Which Oracle parameter can affect this behaviour? the old partition_view_enable parameter does not exist
4) If I go ahead and use this partitioned view, in which cases this can cause problems? At this point, it looks all good if I access the view using indexed columns (of the tables and all tables involved have exactly same indexes).
Thanks in advance

Answer 1

Billy Verreynne is an expert in this area and has been introducing people for years to 'partition views' and you can find many of his previous posts about how and when to use them (including example code) right here in these forums (most of them will be in the SQL and PL/SQL forum).
This feature has been around since Oracle 7 and the 7.3 document that details the info is still at
http://docs.oracle.com/cd/A57673_01/DOC/server/doc/A48506/partview.htm
Here is just one of his many other threads with more example code using five tables.
Table name in from clause