Whole of Government Metadata System Design
LISAsoft delivered the design for a standards-based metadata system that could hold not only information about the many different data sets themselves, but also incorporate business functions. The new design specially negates the duplication that is present in the existing system, to present users with a unified single point of truth for every bit of data held by the government.
The Challenge
To design a system that would allow data held in a variety of organisationally and geographically dispersed databases to be discovered, documented and accessed while minimising disruption to the existing system.
Our Solution
The Government of Victoria is designing a system to improve discovery and access to its information assets. The secondary aim of the project is to rationalise its many metadata systems. The government wanted the ability to create a single point of truth for individual items of data that would be available to all government departments, associated agencies and the general public. A part of the proposal was that this data should be described in a single metadata system. An important consideration for the system developers was that the new system should be developed and implemented with minimum disruption to existing systems and work flows.
LISAsoft was contracted to design the metadata system for Spatial Information Infrastructure, a business unit of the Victorian Department of Sustainability and Environment.
The proposed solution integrates an ANZLIC-compliant metadata schema and the GeoNetwork catalogue application to describe the existing data holdings. Importantly, all the existing Oracle databases, data models and metadata structures are either rationalised into a single repository or preserved. This solution required the development of a customised link between XML metadata catalogues and the relational databases that translate the existing metadata into the ANZLIC-required format.
The design offers significantly simplified maintenance. Metadata already exists in a number of systems. For instance, the identity management system holds contact details, the quality assurance system holds quality information, and so on. Under existing arrangements, this data has to be duplicated in the metadata system. When the information changes, manual intervention is required to update the metadata in every database where that information resides.
LISAsoft’s design takes advantage of XLinks, which provides a link between every instance of a particular record. Change it once and it changes everywhere. All that is required is that the external system provides access to sharable information through a URL – a RESTful interface is perfect for this but any web service that can be referenced in an XLink will do. If the information is exposed in the format used by the metadata standard then no translation of the exposed information is necessary either.
The use of internationally accepted standards on the project will make it much easier to change and adapt the system in the future. It also makes it much easier to meet the client’s requirement that the system can export or import entire metadata records so that individual or grouped records can be inserted into the repository, or distributed to interested parties.