user_part_tables

This question probably applies to other data dictionary views as well.

If one describes user_part_tables, you get:
Name                      Type        =20
------------------------- ------------=20
TABLE_NAME                VARCHAR2(30)=20
PARTITIONING_TYPE         VARCHAR2(7) =20
SUBPARTITIONING_TYPE      VARCHAR2(7) =20
PARTITION_COUNT           NUMBER      =20
DEF_SUBPARTITION_COUNT    NUMBER      =20
PARTITIONING_KEY_COUNT    NUMBER      =20
SUBPARTITIONING_KEY_COUNT NUMBER      =20
...

I was interested in determining where the "DEF_SUBPARTITION_COUNT" was
stored in the underlying system tables (partobj$ I believe). When I
opened the source for view USER_PART_TABLES, I got this:

CREATE OR REPLACE VIEW sys.user_part_tables AS
SELECT o.NAME,
       DECODE(po.parttype, 1, 'RANGE', 2, 'HASH', 3, 'SYSTEM', 4, 'LIST',
=09=09=09=09=09=09=09'UNKNOWN'),
       DECODE(MOD(po.spare2, 256), 0, 'NONE', 2, 'HASH', 3, 'SYSTEM',
                                      4, 'LIST', 'UNKNOWN'),
       po.partcnt, MOD(TRUNC(po.spare2/65536), 65536), po.partkeycols,
...
FROM   sys.obj$ o, sys.partobj$ po, sys.ts$ ts, sys.TAB$ t
...

Ordinarily, if a view has a column named "PARTITIONING_TYPE", I expect
to find, in the view's source, a column or alias that reads
"partitioning_type". Instead, I see unnamed derived columns, and named
columns, that seem to be magically transformed to different names that
show up in user_part_tables.

Which brings me to my question:  What makes the magical column name
transformation happen? What piece of this puzzle am I missing?

--=20
bill coulam
bcoulam@xxxxxxxxx
--
http://www.freelists.org/webpage/oracle-l

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