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The Abstract Data Model

I'd like to use this topic to discuss the abstract data model, as suggested by JohnCaron. I'll try to get some UML here for what I think the ADM should be.

John (and anyone else), can you add UML for other data models like netCDF and HDF5? What I'm concerened about is making sure that our model has a way to represent the concepts present in HDF4/5 and netCDF resonably well. I'd still like to pursue the goal of having HDF4 and HDF5 client libraries...

-- JamesGallagher - 03 Oct 2003


Ok, Im attaching a recent UML diagram of both the current model and a draft of a new model as we merge/munge/mangle with HDF5.

NetCDF current model

N1.png

Draft "NetCDF-4" model

N4.png

-- JohnCaron - 03 Oct 2003

Sequences and Selection

I see sequences as a nice addition that will allow variable length arrays to be effiently represented. Allowing them to be selected in all cases seems to me to be problematic. If I have a large sequence, i cannot efficiently implement the equivilent of a SQL WHERE clause, unless i have built an index. It seems to me that this ability is an addditional capability similar to a function, which should only be allowable if its advertised in the capability object.

-- JohnCaron - 16 Oct 2003

Attachment sort Action Size Date Who Comment
DAP_4_ADM.png manage 6.2 K 03 Oct 2003 - 21:49 JamesGallagher  
N1.png manage 14.0 K 03 Oct 2003 - 23:13 JohnCaron NetCDF object model
N4.png manage 20.4 K 14 Oct 2003 - 21:42 JohnCaron NetCDF-4 (ver2) UML