“Structural metadata comprises most of what is traditionally considered metadata that is organized as the data dictionary, and is derivable from database catalogs. This type of metadata can include:
Data element information, like data element names, types, lengths, definitions, and other usage information;
Table information, including table names; the description of what is modeled by each table; the database in which the table is stored; the physical location, size, and growth rate of the table; the data sources that feed each table; update histories (including the date of last update and of last refresh); the results of the last update; candidate keys; foreign keys; the degrees of the foreign key cardinality (e.g., 1:1 versus 1: many); referential integrity constraints; functional dependencies; and indexes;
Record structure information, which describes the structure of the record; overall record size; whether the record is a variable or static length; all column names, types, descriptions, and sizes; source of values that populate each column; whether a column is an automatically generated unique key; null status; domain restrictions; and validity constraints.”
(David Loshin, Chapter 9 - Metadata,
Business Intelligence (Second Edition), Morgan Kaufmann, 2013, https://doi.org/10.1016/B978-0-12-385889-4.00009-0.)
Proposal:
Work with the group to:
Agree a minimum set of structural metadata (content) that will be collected (and published) across the federated network
Agree an API specification to navigate structural content (including strategy for syndicating tables with 1000’s of rows)
Agree a serialisation format that will allow data catalogues to share content
Content:
Draft to be developed based on work with HDR UK / ADR UK / ONS and NHSE.
The federated model should be based on an ISO11179 model
Initially the model will focus on federating tabular data
Minimum set of structural metadata will be based on CSVW https://w3c.github.io/csvw/primer/
Minimum set of structural metadata to be serialized as JSON-LD