Common Data Model Introduction

The Palace Collection Manager uses a complex data model to represent the current state of:

• All the libraries which use the collection manager.
• All the ebooks available to the patrons of those libraries.
• All the patrons who use the Collection manager, with their active loans and holds.

Looking at the whole data model at once can be overwhelming, so we'll consider it as a few smaller simpler systems:

• Bibliographic metadata
• Licensing
• Works
• Custom lists
• Libraries
• Patrons
• Site configuration
• Background processes

These systems overlap around a few key classes, mainly DataSource, Identifier, LicensePool, and Work.

The code for the data model is https://github.com/NYPL-Simplified/server_core/tree/master/model

in the model package of the server_core project.

This data model is common between the circulation manager and the metadata wrangler (now deprecated) , although some pieces are exclusively used by one component or the other. For example,

• only the collection manager has lanes or patrons, and
• only the metadata wrangler has integration clients.