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An object-relational database system that boasts a vast set of features and a growing community. Complete with a solid architecture that has made it one of the more popular options, it provides reliability, data integrity, and correctness across the database.
Specs
Pros
Pro Object-Oriented Database
You can reuse existing approved design table and extend its capability by inheritance. You can reuse ancestor method byy declaring new trigger for descendant but reuse ancestor trigger procedure. You can add, remove or override column constraint making it differ from its ancestor. Applying OOP with database design help me reuse, extend, and encapsulate business logic and end up a rapid design, and less errants. PostgreSQL is a powerful RDBMS while its OOP is sufficient for OOP modular design. Especially its Open Source ,and free.
Pro Multi-Version Concurrency Control (MVCC)
Postgres uses MVCC. For each user connected to the database the Postgres database shows a snapshot of the database at a particular instance. When the database needs to update an item it will add the newer version and mark the old version as obsolete. This allows the database to save overhead but requires a regulated sweep to delete the old, obsolete data.
Cons
Con Overkill for simple setups
If a database will be doing many simple operations Postgres may be over-kill.