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The Sakai External Database acts as the central source of most, if not all, data external to Sakai. This data is collected from various campus systems, primarily in the form of database tables and queries. The collected data is then transformed into a single source of data presented in a format amenable to the Sakai provider mechanisms.
Requirements
- Support for Varied Data Sourcing: The data Data being provided to the External Database can come from a number of different sourcescampus systems. The Repository database must be able to handle most, if not all, sources of data.Freshness of Data: loading data from linked databases, extract procedures, and other systems. In some cases, the data being provided to Sakai must be as close to the current state of the data source as possible.Query Execution Speedexternal database will locally store and manage data sources.
- Data Refresh: Each source of external data will carry with it a refresh requirement. These refresh requirements may include near-realtime, timed, or ad-hoc scenarios. The external database must be able to fulfil the refresh requirements for each data source.
- System Response: Given that the repository generally aggregates data from external sources, the speed by which aggregated data is provided to Sakai must be optimized.
- Data Synthesis of Heterogeneous Data: In some cases, multiple data sources may contain similar versions of source data. Care must be taken when synthesizing this data for presentation to Sakai.
- Data Availability: Sakai will be a core campus system, and therefore should exhibit maximum availability of data. This availablity requirement extends to the data dependence on source systems. If the source system does not provide a sufficient degree of availability, measures must be taken to ensure the data is avaiable when the source system is offline.
Achitectural Design
The External Database will be hosted on a single database server. This database will, at one end, allow data to be fed into it from various source systems on campus, and at the other end will provide a database schema readable by Sakai, and formatted to be as efficient as possible in the Sakai structure.
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