What is Postgresql?

PostgreSQL (post-gress-Q-L) is a powerful, open source object-relational database system. It has more than 15 years of active development and a proven architecture that has earned it a strong reputation for reliability, data integrity, and correctness. This system runs on the all major operating systems, including UNIX (AIX, BSD, HP-UX, SGI IRIX, Mac OS X, Solaris, Tru64), Windows, and Linux. It is fully ACID compliant, has full support for foreign keys, joins, views, triggers, and stored procedures (in multiple languages). It also includes most of the SQL data types, including CHAR, VARCHAR, DATE, INTERVAL, INTEGER, NUMERIC, BOOLEAN and TIMESTAMP. It supports storage of binary large objects, including pictures, sounds, or video. The native programming interfaces of this system include for C/C++, Net, Perl, Python, Java,  Ruby, Tcl, ODBC, among others, and expectational database. It can be configured through configuration files.

Postgresql’s configuration file

PostgreSQL.conf  include files or directories can be used to logically separate portions of the database configuration, rather than having a single large PostgreSQL.conf file. Consider that a company that has two database servers, each database with a different amount of limit memory.

There are active post-gress-Q-L instances in production environments that manage many terabytes of data, as well as clusters managing petabytes. Some general PostgreSQL limits are included in the table below.

Limit Value
Maximum Database Size Unlimited
Maximum Table Size 32 TB
Maximum Row Size 1.6 TB
Maximum Field Size 1 GB
Maximum Rows per Table Unlimited
Maximum Columns per Table 250 – 1600 depending on column types
Maximum Indexes per Table Unlimited

Command to access PostgreSQL.conf file

/var/lib/pgsql/data/postgresql.conf