I know that on my Mac the tables are kept in the data directory
> /Users/martinmueller/Library/Application Support/Postgres/var-13. If I go
> there I see that internally the tables have numbers. Somewhere in the
> system there must be a table that maps the name I gave to table X to the
> numerical inside the database.
>
Check the pg_class table in the system catalog. The numeric value is the
OID.
https://www.postgresql.org/docs/14/catalog-pg-class.html
Craig
>