Difference between Namespace and Folders in Frame work Manager

[sreejithhk]

Hi,

When i was creating query subjects in FM, this doubt came through me..

Why would u need a namespace to create ur query subjects when we have the folder used to serve the purpose..

can u provide me more details on this..

Thanks,
Sreejith H

[Lynn]

There are lots of posts and information about best practices regarding namespaces and modeling such as having a physical layer, etc. I suggest you review the FM user guide and related best practice documents to get a better understanding of the concepts.

In simplest terms, a namespace becomes part of what identifies an item while a folder does not.

In the relational world an item is identified as:

[Namespace].[Query Subject].[Query Item]

In the dimensional world an item is identified as:

[Namespace].[Dimension].[Hierarchy].[Level]

You can organize things into folders but it doesn't affect how an item is referenced. This means you could have a query subject or a query item with the same name in two different namespaces. If you had a single namespace and only folders to organize things then every name has to be unique.

[wyconian]

I'd suggest that namespaces should be used to collect subject related query subjects together e.g. you may have a sales namespace which holds the sales data mart etc.

Folders are more typically used to organise the visual representation of data e.g. within the sales namespace you may have a customer folder which contains the customer, customer address, customer contact query subjects etc and then another folder which holds product related query subjects.

Folders can also be used within a query subject to organise query items e.g. in my calendar query subject I have folders for year, quarter, month etc attributes.

I would normally only use folders to visual orgainse query subjects or query items.  My approach is to try to make sure that when a user opens a package (or a namespace) they don't need to scroll to see all the intial objects.

Bear in mind that if you change the name of a namespace you will chaneg the identifier of all items within that namespace (as Lynn said the namespace is part of the identifer) which could break reports but changing the name of a folder has no impact.

Folders and namespaces also have an impact on joins.  If you get to a situation where you have mutliple data paths the joins within a folder are evaluated before the joins within a namespace.  There are times when that can be useful.

Hope that helps, good luck