Chaining in spatial enabled tables

Question

SQL Analyze indicates in a tuning session that there are a considerable amount of chained rows in a table that has a spatial column in it. (47 000 chained rows, returned 712 000 rows)
However, when I analyze the chained rows in the table in an "old" way (analyze table alueet list chained rows;) I only get 11 rows.
Has this mismatch anything to do with Oracle Spatial? In general, should I try to remove chained rows in a spatially enabled table?
Regards,
Pirkko Laurila (dba)

Answer 1

Shawn
The following code snippet will achieve what you want -
create or replace view myviewForLatestInLIVE as
select g.*
from mytable_hist g
where g.workspace = 'LIVE' and
g.retireTime is null;
NOTE: The above view will show all the latest records in the
LIVE workspace i.e. the same records as:
exec dbms_wm.gotoWorkspace('LIVE');
select * from mytable;
Couple of points to note (regarding your view definition) :
With view_wo_overwrite, you can have multiple copies of a row IN
the SAME version. view_w_overwrite will keep only one copy of a
row in a version.
Retire time is NULL when a row is not retired. If a row is
retired, there will ALWAYS be another, newer version of the row
with a NULL for retire time.
For non-LIVE workspaces, to achieve what you want is a little
more involved. The code snippet below will do it -
create or replace view LatestDataFromW1 as
select g.*
from mytable_hist g,
(select i, max(createTime) ct
from mytable_hist
where version in (
select version from all_version_hview
start with version =
(select max(version)
from all_version_hview
where workspace = 'w1')
connect by prior parent_version = version)
group by i ) p
where g.i = p.i and g.createTime = p.ct;
Here the workspace name is w1.
Let me know if you have any other questions / suggestions.
regards
Arun