What is meant by the term core schemas and how does one decide which schemas to include or exclude?
The term core schemas is used [by TOYS] to mean the set of schemas being captured, compared or synchronized. Often, tables in the core schemas have foreign keys that reference external schema [i.e. schema that are not in the core schemas]. Additionally, external schemas may reference tables in the core schemas. These are refered to [in the TOYS documentation] as outward references and inward references respectively. Where cyclic references exist [e.g. schema A references schema B and vice-versa] the schemas should usually be compared and upgraded as a group. If for example, all references in schema X are outwards to schemas A, B or C then schema X can quite happily be compared and synchronised on its own. There is however an implied dependency of schema X on schemas A, B and C and thus the latter three schemas will most likely need to be synchronised prior to synchronizing schema X. It should be understood that the synchronization of schemas A, B and C may drop and replace inward refer
