Обсуждение: Multiple Schema and extensions

Is it the case that extensions can be added to only one schema?  If so, what is the recommended practice for accessing
afunction from an extension in multiple schemas? 

Is it *ok* to load the extension in the pg_catalog schema so functions can be accessed by unqualified names?  Is it
*better*to have a separate schema for functions and use qualified names to access?  What is the general accepted
practice?

As a side note:
ALTER EXTENSION foo ADD SCHEMA bar
What the heck does this do?  AFICS, it has no effect on the visibility of an extension function in the *added* schema.

thanks
alan

Alan Nilsson wrote:
> Is it the case that extensions can be added to only one schema?  If
so, what is the recommended
> practice for accessing a function from an extension in multiple
schemas?

Yes, a (relocatable) extension can belong to only one schema.
There are two ways to access the functions:
1) Use qualified names.
2) Set search_path to contain the schema.

> Is it *ok* to load the extension in the pg_catalog schema so functions
can be accessed by unqualified
> names?  Is it *better* to have a separate schema for functions and use
qualified names to access?
> What is the general accepted practice?

No, that is not ok.
pg_catalog is only for system objects.
You should use schema "public" - that is in search_path by
default, and everybody can use it.

> As a side note:
> ALTER EXTENSION foo ADD SCHEMA bar
> What the heck does this do?  AFICS, it has no effect on the visibility
of an extension function in the
> *added* schema.

This makes "bar" belong to extension "foo", not the other way around.
The effect is that
a) "bar" will not be dumped by pg_dump
b) "DROP EXTENSION foo" will drop schema "bar"

Yours,
Laurenz Albe