[Mondrian] Dimension member caching

Julian Hyde jhyde at pentaho.com
Wed Aug 6 15:06:16 EDT 2008

You should all be aware that this is an incomplete feature. The API and
underlying design are sound -- I spent several iterations with the developer
Marc Berkowitz -- but there are several known bugs and doubtless a few
unknown ones too. It may be complete in mondrian-3.1, but we are not
committing to this. Use at your own risk.
Marc, can you answer Michael's questions? Also, if you have some
documentation for this, please post it. I would like the final feature to
have developer-oriented documentation which is an extension to
Michael and Haridasan, Do you have some time available to help Marc test &
document this?


From: mondrian-bounces at pentaho.org [mailto:mondrian-bounces at pentaho.org] On
Behalf Of Haridasan T
Sent: Wednesday, August 06, 2008 7:46 AM
To: Mondrian developer mailing list
Subject: Re: [Mondrian] Dimension member caching

This is very interesting and important, when it comes to large data sets.  I
failed to establish a partial cleaning of Cache , now I am using full cache
cleaqning inorder to get results always properly. Any suggestion ?

On 8/6/08, michael.pflug at thomsonreuters.com
<michael.pflug at thomsonreuters.com> wrote: 

Hi All -

I plan to utilize the dimension member caching feature implemented
with check in 10788 but I have a few questions I'm hoping the community
can help me out with before I get too far:

1)  The feature is dependant on having the property
mondrian.rolap.EnableRolapCubeMemberCache=false, but I don't fully
understand the consequences of setting this property to false.  Can
anyone elaborate?

2)  In the unit test MemberCacheControlTest.testDeleteCommand(), the
test allows two possible outcomes - one that flushes only the desired
member and one that flushes the entire level.  Walking through the test
it always seems to flush the entire level which is arguably less
desirable. Does anyone understand this behavior?

3)  The code specifically does not allow flushing of parent-child
dimensions and, as luck would have it, the dimension I am most
interested in flushing is parent-child.  There is no comment as to why
parent-child isn't allowed - can anyone fill me in on what the
difficultly might be in implementing this?

4)  Finally, my specific use case is that I have a volatile dimension
that I wish never to be cached.  I could clear the cache manually before
each query, but I'd rather specify an optional property in my schema
telling Mondrian to never cache the dimension.  Does anyone have any
objections to that implementation?

Thanks in advance for your time!

Mike Pflug
Thomson Reuters

Mondrian mailing list
Mondrian at pentaho.org

-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.pentaho.org/pipermail/mondrian/attachments/20080806/f5f2fe93/attachment.html 

More information about the Mondrian mailing list