OrientDB vs Postgres

This database is primarily, or historically, thought of as a graph database. However, it is actually a multi-model database that supports a variety of noSQL models (key-value, document, etc.).

The Apache 2 license is one of the most liberal licenses. You can use OrientDB for any purpose for free.

Unlike other NoSql databases, OrientDB offers clustering support for free. Furthermore, it's not a basic Master/Slave, but it supports Master-Master replication + Sharding.

It can be queried in a number of ways, but the ability to query with SQL makes it a bit more familiar to use.

OrientDB is incredibly scalable thanks to its multi-master replication. All nodes in a cluster can both read and write.

Full text search support is available when using Lucene based indexing algorithm.

OrientDB is very fast, especially when it comes to relationships between records (or "links").

The Community Edition is free and covers many features, but an Enterprise Edition is available (prices are transparent, published online) with 24x7 support.

Built by passionate developers, available for free, and is well supported by its active community.

With the extensive SQL support and migration tools, Postgres users are easily able to migrate their databases over to the Postgres database with little effort.

JSON support allows for Postgres to transfer data as raw text and without attributes and markup overhead. This will result in new levels of speed, efficiency and flexibility for developers.

Continues to work well under low or heavy loads in order to meet the users' need.

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.

Built in, so users won't have to worry about atomicity, consistency, isolation and the durability of the database.

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.

"There are interfaces for Java (JDBC), ODBC, Perl, Python, Ruby, C, C++, PHP, Lisp, Scheme, and Qt just to name a few."

Unlike MySQL, you generally don't spend time on hinting the query planner in order to make PostGres perform well.

For example:

INSERT INTO table (field_1, field_2, field_3) VALUES (value_1, value_2, value_3) RETURNING id;