Is PostgreSQL a NoSQL database? [closed]
You have been confused my marketing and buzzwords.
“NoSQL” is a buzzword describing a diverse collection of database systems that focus on “semi-structured” data (that do not fit well into a tabular representation), sharding and high concurrency at the expense of transactional integrity and consistency, the latter being among the basic tenets of relational database management systems (RDBMS).
Since SQL is the language normally used to interact with an RDBMS, the term “NoSQL” is used as a name for all these systems. Perhaps the name was also chosen because SQL, being verbose and often hard to understand, evokes negative reactions in many programmers.
Now PostgreSQL, like many other RDBMS, has added support for JSON data, which is the most popular format for semi-structured data commonly stored in NoSQL systems. Now you can say that PostgreSQL supports a certain feature commonly found in NoSQL databases.
Still, SQL is the only way to interact with a PostgreSQL database, so you couldn't call it a NoSQL database and keep a straight face unless you were in marketing.
Postgres Plus is a closed source fork of PostgreSQL, so the same applies to it.
PostgreSQL is not NoSQL.
PostgreSQL is a classical, relational database server (and syntax) supporting most of the SQL standards.
On a sidenote, I suggest doing some research into the differences and advantages. They both have a solid place and time.
PostgreSQL prides itself in standards compliance. Its SQL implementation strongly conforms to the ANSI-SQL:2008 standard. It has full support for subqueries (including subselects in the FROM clause), read-committed and serializable transaction isolation levels. And while PostgreSQL has a fully relational system catalog which itself supports multiple schemas per database, its catalog is also accessible through the Information Schema as defined in the SQL standard.