Overview:PostgreSQL is an object-relational database management system with an emphasis on extensibility and standards-compliance. PostgreSQL is cross-platform and runs on many operating systems including Linux, FreeBSD, Solaris, and Microsoft Windows. It can handle workloads ranging from small single-machine applications to large internet-facing applications with many concurrent users. Recent versions also provide replication of the database itself for security and scalability. PostgreSQL supports standards such as ANSI SQL and SQL/MED and yet is highly extensible with support for over 12 procedural languages, GIN and GIST Indexes, Spatial data support, and multiple NoSQL-similar features for document or key-value based applications.