When I SELECT encoding FROM pg_database, I get a number. When I type \l,
encodings are displayed as a human-readable string. I do not find where these
strings are stored. I've read "PostgreSQL 7.2.1 Developer's Guide", Chapter 3.
"System Catalogs" but without result.
PS: this is because I wonder why I can enter composed characters like ç or é
when the database is in SQL_ASCII but not when it is UNICODE.