Postgres

PostgreSQL is a powerful, open source object-relational database system. It supports storage of binary large objects, including pictures, sounds, or video. It compatible with may of programming interfaces like PHP, C/C++, Java, .Net, Perl, Python, Ruby, Tcl, ODBC, among others, and exceptional documentation. Postgres is better then Mysql when using many subqueries and Joins.

For newbie: PostgreSQL installation and settings on Ubuntu 12.04

These are following steps for exporting csv from table:

sudo -u postgres psql DBNAME

Note: Selecting DB is best way to specify which DB's tables you want to export.

COPY tablename TO '/home/username/filename.csv' DELIMITER ',' CSV HEADER;

Note: You need to specify table name and file name.

Reference
About PostgresSQL