PostgreSQL 18 introduces temporal constraints that simplify managing time-related data, allowing developers to maintain referential integrity across temporal relationships with ease. By utilizing GiST indexes and the WITHOUT OVERLAPS constraint, developers can efficiently handle overlapping time periods in applications without complex coding.

Maintaining consistency in a system comprised of separate databases can be challenging, particularly in the absence of transactions. The article discusses the importance of defining a system of record versus a system of reference and emphasizes the Write Last, Read First principle to ensure safety properties like consistency and traceability in financial transactions.