Relational Database Patterns?

pole asks: "Are there common relational database patterns (schemas, stored procedures, triggers, etc.) which can be effectively reused? These could be "upsert" (update or insert) patterns, temporal database patterns (historical data such as human resources records or time-series data), referential integrity patterns or even code generation patterns (good programmers don't reuse code via cut-and-paste). Can you think of useful RDMBS patterns? Would be great if these were part of a repository with use-cases and examples that actually worked. Is there such a beast?"