When a schema instantiation on the RPS node includes changes to the RPS mapping, the DDL scripts to define new tables or redefine existing tables are generated by the RPS node, and when possible, applied to the target relational schema.
When an RPS mapping is versioned, a mapping check audit record is written to the journal on the primary database. The mapping check audit record contains a list of schemas and RPS mappings that were versioned. This audit record is recognized and replayed by RPS nodes and ignored by native SDS databases.
When an RPS node replays a mapping check record and a versioned RPS mapping matches the configured mapping, the current and latest versions of the RPS map are compared. Any differences are used to generate a Data Definition Language (DDL) script that can be applied to the RDBMS target database, to restore schema consistency.
Replaying a schema instantiation on an RPS node configured for Full or Mapped Extent replication also performs any required reorganization to persistent objects replicated in the database. A database configured for Working Set replication skips reorganization steps, but replays other required aspects of the schema instantiation.
Replaying a schema instantiation requires that the Datapump application and database tracking are halted. This halt in tracking occurs even if no changes to the target relational schema are required, in order to satisfy standard requirements for transition to a new schema version.
The Datapump application and database tracking can be automatically restarted when the conditions documented in the following subsections are met.