btree_gist provides GiST index operator classes that implement B-tree equivalent behavior for the data types int2,

The pg_freespacemap module provides a means for examining the free space map (FSM). It provides a function called pg_freespace

dict_xsyn (Extended Synonym Dictionary) is an example of an add-on dictionary template for full-text search. This dictionary type replaces words

The tablefunc module includes various functions that return tables (that is, multiple rows). These functions are useful both in their own right

The lo module provides support for managing Large Objects (also called LOs or BLOBs). This includes a data type lo and

sepgsql is a loadable module that supports label-based mandatory access control (MAC) based on SELinux security

The citext module provides a case-insensitive character string type, citext. Essentially, it internally calls

The postgres_fdw module provides the foreign-data wrapper postgres_fdw, which can be used to access data stored in

btree_gin provides sample GIN operator classes that implement B-tree equivalent behavior for the data types int2,

The pageinspect module provides functions that allow you to inspect the contents of database pages at a low level, which is useful for debugging