pgSpherehttp://www.oschina.net/p/pgsphere pgSphere 为 PostgreSQL 数据库提供球面数据类型，函数，和运算函数。 Multicornhttp://www.oschina.net/p/multicorn Multicorn 是一个 PostgreSQL 9.1+ 的扩展模块，用于简化外部数据封装开发，允许开发者使用 Python 编程语言开发。 - oracle_fdw – connects to Oracle databases.
- mysql_fdw – connects to MySQL databases.
- tds_fdw – connects to Sybase and Microsoft SQL Server databases.
- odbc_fdw – connects to any ODBC source.
- couchdb_fdw – connects to CouchDB databases.
- redis_fdw – connects to Redis databases.
- twitter_fdw – fetches messages from Twitter.
- ldap_fdw – queries LDAP servers.
- file_fdw – access data files in the server’s file system and query them as tables.
- file_fixed_length_record_fdw – reads flat files with columns of fixed width.
- PGStrom – uses GPU devices to accelerate sequential scan on massive amount of records with complex qualifiers.
- s3_fdw – reads files located in Amazon S3.
- www_fdw – accesses web services as a data source.
- multicorn.sqlalchemyfdw – used to access data stored in any database supported by the sqlalchemy python toolkit, such as MySQL, SQLite, Oracle, Microsoft SQL Server and many others.
- multicorn.fsfdw – used to access data stored in various files, in a filesystem.
- multicorn.csvfdw – used to access data stored in CSV files.
- multicorn.rssfdw – used to access items from an RSS feed.
Hstorehttp://www.postgresql.org/docs/9.1/static/hstore.html 该模块为 PostgreSQL 提供存储Key-Value数据的功能，你可以定义 hstore 数据列来存储这样的数据，并可对这些数据进行分组、排序和唯一检索的查询。 Intarrayhttp://www.postgresql.org/docs/9.1/static/intarray.html intarray 模块提供一系列有用的函数和运算用于操作整数数组，同时支持索引搜索。 如果数组中包含 null 元素，那么所有的这些操作都将抛出错误。当我开发一个简单的图像比较功能时，我会使用这个扩展 (http://leopard.in.ua/2010/12/09/bystroe-sravnenie-izobrazhenij-s-pomoshhyu-rubyphp-i-postgresql/, 俄文). Dblinkhttp://www.postgresql.org/docs/9.1/static/dblink.html Dblink 让你可以在 PostgreSQL 连接会话中支持连接到其他 PG 数据库，同时支持自主事务 autonomous transactions (like in Oracle). That’s all folks! | 
