I have worked with linked universes and they worked very well with little problem for us, except for one thing. We had two unlinked universes that were identical except for the joins (inner vs. outer). We decided to replace these with a master universe and two derived universes to make maintainence easier. There was no problem until we went in to an existing report and tried to change the universe from the unlinked version to the linked version. Keep in mind the universes were identical. When we would change the universe from the unlinked to the linked, it would completely wipe out our data provider. When we pulled the data provider up, it was completely empty, just as it would look for a brand new report. If we went from unlinked universe to unlinked universe, no problem. If we went from linked universe to linked universe, no problem. If we went from unlinked to linked though, brick wall!!
I talked to BO Support about it, they didn’t seem to be sure what would cause it. They had us try a couple of different things but nothing worked. We ended up having to rebuild each data provider, which, needless to say, was a lot of work!!
Our client would like us to use Linked Universes. Though we have heard of
them corrupting entire repositories. If anyone has any information on this
I would appreciate it. Just wanting to be careful and if there is an existing problem we would love to avoid it.
Our client would like us to use Linked Universes. Though we have heard of them corrupting entire repositories. If anyone has any information on this I would appreciate it. Just wanting to be careful and if there is an existing problem we would love to avoid it.
We are using linked universes. The major problem that we faced were:
You cannot migrate linked universes between different repositories unless the master or core universe is included in the derived universe. They can be migrated only between universe domains in the same repository as claimed by BO documentation although we were not able to do it successfully.
migrating these linked universe from a development domain to a production domain. It does not work as specified in the documentation. We had contacted BO about it. The BO representative could replicate the problem in US. But when they sent the problem to France they could not replicate it. They had a feeling that this problem was fixed in a later release that was used in France (4.1.1 if I remember right). We never got around to testing the new release and we used another method to get around this bug by the time BO responded.To test migration one has to be careful because the report keeps running against the earlier domain master universe even after changing the universe to new domain’s universe. This can be extremely deceptive.
If you delete the master and export another master with the same universe name then you can get into serious problem.This is because BO create a new universe ID. Objects in the report are accessed through the universe id/object ids. All the reports that may fail. Any new version of the universe should overwrite the old version on export. This ensures that the universe id remains the same.
No objects in the master should be deleted and recreated even with the same name as the one you deleted. This leads to new object IDs in the repositories and if you try to use a report with the object it will not be able access these objects. If you have to make changes in the object instead of deleting it and re-creating these they should be re-mapped to say new fields in maybe new tables. This ensures that object id’s remain the same.
It is also advisable to keep a backup of the repository and may be the BOmain keys etc. in case of any problems.We never faced a problem of repository corruption as you have stated.
These are some of the main problems we faced. I would suggest you to contact a Knowledgeable BO representative before using linked universe to get a handle on the do’s and dont’s. I wish they can make these as part of their documentation in future.
Manoj
______________________________ Reply Separator _________________________________
Author: “Brian M. Peterson” bpeterson@BRAUNTECH.COM at Internet
Date: 7/27/98 10:33 AM
Not a problem yet,
Our client would like us to use Linked Universes. Though we have heard of them corrupting entire repositories. If anyone has any information on this
I am not sure how the unlinked and linked universes can be identical as you state. The objects in the unlinked universe will have different object ids because they are all in one universe while objects in the master universe and derived universe will necesarily be different in the repository. May be that explains the loss of dataprovider.
Manoj
______________________________ Reply Separator _________________________________
Author: “Carter; Maria” mcarter@HRSERV2.IMS.ATT.COM at Internet
Date: 7/27/98 1:31 PM
Brian,
I have worked with linked universes and they worked very well with little problem for us, except for one thing. We had two unlinked universes that were identical except for the joins (inner vs. outer). We decided to replace these with a master universe and two derived universes to make maintainence easier. There was no problem until we
Our client would like us to use Linked Universes. Though we have heard of
them corrupting entire repositories. If anyone has any information on this
I would appreciate it. Just wanting to be careful and if there is an existing problem we would love to avoid it.
There are some good points there…
One other thing to watch for is UNLINKING a DErived and CORE universe.
If both the Derived and the Core universe contain a Common table, you will have problems Unlinking the Core Universe. When you try to unlink, you will get an error message along the lines of: Cannot Unlink the Universe- Some of the Objects are Currently in Use.
I have found the only way to unlink was to ‘include’ the Core universe and drop the tables/objects that I knew were from the Core Universe.
We use Linked Universes extensively with no problems (to date!).
A big advantage for us is the metadata (universe object descriptions), and the fact that they do not need to be duplicated in multiple Universes with the same tables.
To our understanding they should be identical because when we created the master universe, we made a windows copy of one of the existing unlinked universes and then made our changes from there. The only changes were joins. No new objects, no new tables so the objects ids should have remained the same. We were told that if we would have done a save as…then the object ids would differ but a windows copy of the universe should retain the same object ids.
I am not sure how the unlinked and linked universes can be identical as you
state. The objects in the unlinked universe will have different object ids
because they are all in one universe while objects in the master universe and
derived universe will necesarily be different in the repository. May be that
explains the loss of dataprovider.
Manoj
Brian,
I have worked with linked universes and they worked very well with
little problem for us, except for one thing. We had two unlinked universes that were identical except for the joins (inner vs. outer).
We decided to replace these with a master universe and two derived
universes to make maintainence easier. There was no problem until we
Our client would like us to use Linked Universes. Though we have heard of
them corrupting entire repositories. If anyone has any information
on
this
I would appreciate it. Just wanting to be careful and if there is
an
existing problem we would love to avoid it.
From a question about linked universes, and the pros and cons, came this
exerpt from Manoj Chandra:
No objects in the master should be deleted and recreated even with the
same
name as the one you deleted. This leads to new object IDs in the repositories and if you try to use a report with the object it will not be able access
these
objects. If you have to make changes in the object instead of deleting it and re-creating these they should be re-mapped to say new fields in maybe new tables. This ensures that object id’s remain the same.
Is this true for all universes, or only the linked ones?
If you must make changes to an object which has been used in a report, it is best to modify the existing object. Deleting it will render the object obsolete, even if you re-create it with the same name.
From a question about linked universes, and the pros and cons, came this exerpt from Manoj Chandra:
No objects in the master should be deleted and recreated even with the
same
name as the one you deleted. This leads to new object IDs in the
repositories
and if you try to use a report with the object it will not be able access
these
objects. If you have to make changes in the object instead of deleting it
and
re-creating these they should be re-mapped to say new fields in maybe new tables. This ensures that object id’s remain the same.
Is this true for all universes, or only the linked ones?
