Using psql how do I list extensions installed in a database?

问题

How do I list all extensions that are already installed in a database or schema from psql?

See also

• Finding a list of available extensions that PostgreSQL ships with

回答1:

In psql that would be

\dx

See the manual for details: http://www.postgresql.org/docs/current/static/app-psql.html

Doing it in plain SQL it would be a select on pg_extension:

SELECT * 
FROM pg_extension

http://www.postgresql.org/docs/current/static/catalog-pg-extension.html

回答2:

Additionally if you want to know which extensions are available on your server: SELECT * FROM pg_available_extensions

回答3:

This SQL query gives output similar to \dx:

SELECT e.extname AS "Name", e.extversion AS "Version", n.nspname AS "Schema", c.description AS "Description" 
FROM pg_catalog.pg_extension e 
LEFT JOIN pg_catalog.pg_namespace n ON n.oid = e.extnamespace 
LEFT JOIN pg_catalog.pg_description c ON c.objoid = e.oid AND c.classoid = 'pg_catalog.pg_extension'::pg_catalog.regclass 
ORDER BY 1;

Thanks to https://blog.dbi-services.com/listing-the-extensions-available-in-postgresql/

来源：https://stackoverflow.com/questions/21799956/using-psql-how-do-i-list-extensions-installed-in-a-database