Logical reporting cube - slow data retrieval

Question

OLAP 11.2
I have seen discussion on this board recommending using a logical reporting cube to expose data if there are multiple physical cubes in the workspace.  The problem I am having is that the data retrieval seems very slow from the logical cube while it is fine if I select from the actual physical cubes. Here is my set up.
Physical cube A - Dimensions x,y,z
Physical Cube B - Dimension w,x
Physical Cube C, Dimension y,z
Logical Cube  D. Dimension w,x,y,z with calculated measures mapped to the measures from the cubes A,B and C as well as some other calculated measures based on these.
Data retrieval from A, B and C is quick but the query hangs if I select certain measures from D. On some measures, it seems to work without issues.
Is there some thing I am missing?
Thanks,
Usman

Answer 1

Usman,
Its probably because of LOOP_VAR  and/or LOOP_DENSE settings of the measures in your Logical reporting cube.
I have posted on this topic in the past.   With this new Oracle-Forum interface its difficult to search old postings.
(1). Execute the following:
exec dbms_cube_log.enable(dbms_cube_log.TYPE_OPERATIONS, dbms_cube_log.TARGET_TABLE, dbms_cube_log.LEVEL_HIGH);
(2). Run the olap query.
(3). Query CUBE_OPERATIONS_LOG table
select *
from cube_operations_log
where   upper(suboperation) like '%LOOP%' or upper(name) like '%LOOP%'
order by time;
Tell us what you see in the 'NAME  and  'VALUE'  columns, after your query execution.
Also take a look at this post:   Delay when querying from CUBE_TABLE object, what is it?
Nasar