if hstore is installed in public schema, sometimes You have to use public.hstore syntax (fully qualified name) - this depends on your search_path setting.
in your example it looks like hstore is installed, but question is: where is it?
You can find this info using SQL like this one:
SELECT * FROM
pg_extension e INNER JOIN pg_namespace n ON (e.extnamespace = n.oid)
I have 2 databases running in a single server; and I installed extension 'hstore' to one database and it works fine. When I tried to use the same extension in another database, it gives an error saying 'extension does not exist'; nor it allow to install as it complains about its existence.
Any help ?
db1=# CREATE EXTENSION hstore; ERROR: type "hstore" already exists db1=# DROP EXTENSION hstore; ERROR: extension "hstore" does not exist db1=# create table foo(id hstore); ERROR: type "hstore" is only a shell LINE 1: create table foo(id hstore); ^