RE: W3C SDWIG - Ontology for RDF Data Cube dicing

Hi Rob,

Thanks for these useful and informed comments.

This suggests to me that I put this work item into the W3C SDWIG ‘funnel’.

Chris

From: Rob Atkinson <robatkinson101@gmail.com>
Sent: 04 July 2018 22:48
To: Little, Chris <chris.little@metoffice.gov.uk>
Cc: Bill Roberts - Swirrl IT Limited (hello@swirrl.com) <hello@swirrl.com>; Rob Atkinson <rob@metalinkage.com.au>; public-sdwig@w3.org
Subject: Re: W3C SDWIG - Ontology for RDF Data Cube dicing

Previously i have played with url templates referencing qb components...

This supports arbitrary service interfaces. The dxwg work on profile descriptions might be a pathway to classifying such services.  Documenting such services, and various subset relationships is important and not well supported, but possibly some of the DCAT work will help.. but probably just recommend using an external vocab. So leveraging that to justify this new work makes sense.

Qb metadata for subsets once transferred is another concern, but a use case for the same vocabulary

Available and keen to support any activity in this space.

Rob






On Thu, 5 Jul 2018, 03:41 Little, Chris <chris.little@metoffice.gov.uk<mailto:chris.little@metoffice.gov.uk>> wrote:
Dear Rob and Bill,

Do you think  that there is any mileage in defining an ontology, in OWL or SKOS I suppose, for 'dicing' a data cube?

My understanding is that the RDF definition supports 'slicing' across one dimension  or more, reducing the dimensionality of the data cube. Originally when the RDF ontology was proposed, the UN SDMX statisticians could not agree on further sub-setting or summarising.

At the OGC Tech Conference in March in Orléans, there was recognition that there was a commonality underlying all the proposed big data cubes, geospatial data cubes, map tiles, vector tile sets, data partitions, result paging, etc.

With the OGC enthusiasm for the newer, more flexible, less schematic, more RESTful, WFS3, there seems to be a push to review the entities that appear in various web services and generalising them to use across a variety of services and APIs.

It appears to me that there are some very common patterns in data partitioning that could be re-used, especially if the concepts and terminology were honed. E.g. along one dimension, partition according to item count (give me the first 10 000 values, then the next 10 000, ...) or according to measure along the dimension (give me everything between 0.0 to 45.0, then 45.0 to 90.0, ...) or according to data volume (give me the first 10MB of data values, then the next 10MB, .. and by the way, tell me the index value of the dimension boundaries)

These patterns could be applied in 1D (timeseries), 2D (map tiles), 3D (Cesium), or more.

I see this as being complementary and orthogonal to the QB4ST work.

Does all that make sense? Do you think it worthwhile doing?

Chris

Chris Little BA, MSc, FRMetS, MBCS
Chair, OGC Meteorology & Oceanography Domain Working Group
Chair, OGC Temporal DWG
Member, OGC Architecture Board

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