Package "postgresql-contrib-9.1"

additional facilities for PostgreSQL
The PostgreSQL contrib package provides several additional features
for the PostgreSQL database. This version is built to work with the
server package postgresql-9.1. contrib often serves as a testbed for
features before they are adopted into PostgreSQL proper:

adminpack - File and log manipulation routines, used by pgAdmin
btree_gist - B-Tree indexing using GiST (Generalised Search Tree)
chkpass - An auto-encrypted password datatype
cube - Multidimensional-cube datatype (GiST indexing example)
dblink - Functions to return results from a remote database
earthdistance - Operator for computing the distance (in miles) between
two points on the earth's surface
fuzzystrmatch - Levenshtein, metaphone, and soundex fuzzy string matching
hstore - Store (key, value) pairs
intagg - Integer aggregator/enumerator
_int - Index support for arrays of int4, using GiST (benchmark
needs the libdbd-pg-perl package)
isn - type extensions for ISBN, ISSN, ISMN, EAN13 product numbers
lo - Large Object maintenance
ltree - Tree-like data structures
oid2name - Maps OIDs to table names
pageinspect - Inspection of database pages
passwordcheck - Simple password strength checker
pg_buffercache - Real time queries on the shared buffer cache
pg_freespacemap- Displays the contents of the free space map (FSM)
pg_trgm - Determine the similarity of text based on trigram matching
pg_standby - Create a warm stand-by server
pgbench - TPC-B like benchmark
pgcrypto - Cryptographic functions
pgrowlocks - A function to return row locking information
pgstattuple - Returns the percentage of dead tuples in a table; this
indicates whether a vacuum is required.
seg - Confidence-interval datatype (GiST indexing example)
spi - PostgreSQL Server Programming Interface; 4 examples of
its use:
autoinc - A function for implementing AUTOINCREMENT/
IDENTITY
insert_username - function for inserting user names
moddatetime - Update modification timestamps
refint - Functions for implementing referential
integrity (foreign keys). Note that this is
now superseded by built-in referential
integrity.
timetravel - Re-implements in user code the time travel
feature that was removed in 6.3.
tablefunc - examples of functions returning tables
uuid-ossp - UUID generation functions
vacuumlo - Remove orphaned large objects

PostgreSQL is an object-relational SQL database management system.