What is the deal with the "invisible schema" pg_catalog? If I run this query:
SELECT schemaname, tablename, indexname, indexdef FROM pg_indexes ORDER BY schemaname ASC, tablename ASC, indexname ASC;

It returns a ton of records for the nonexistent schema &quot;pg_catalog&quot;. It's not a schema in my database. I assume it's some kind of internal, &quot;secret&quot; schema, but I find no mention of it in the PG manual when I searched for it before asking.
It's not a schema in my database.

Yes, it is. And it's neither &quot;invisible&quot; nor undocumented:
Quote from the manual

In addition to public and user-created schemas, each database contains a pg_catalog schema, which contains the system tables and all the built-in data types, functions, and operators. pg_catalog is always effectively part of the search path.

All views and tables in the pg_catalog schema are documented here