1) Supports large part of SQL standards like Complex queries, stored procedures.2) As source code is free and open, it can be easily distributed, modified and extended according to user requirements.3) PostgreSQL also proves to be a cost-effective solution for organization's as this product is designed and created to have much lower maintenance without compromising on features.4) Excellent GUI tools available for PostgreSQL like pgAdmin III.
Room for Improvement:
1) It tends to be slower when processing a large number of records.2) Does not support the entire ANSI SQL 92' standard.3) More open source applications (software stacks) supports MySQL, but some of them may not support PostgreSQL4) Comparatively small user community than MySQL 5) Installation and setup is bit complex and requires technical know how. Though PostgreSQL is comparatively slower than MySQL, but can handle a heavier workload, and also supports various SQL features like foreign keys, triggers, stored procedures and transaction rollback.
Great Documentation, active community support, excellent management & development tools and availability on various platforms makes PostgreSQL a good data base management system.