Query below lists tables with their number of foreign keys and number of tables they refer to.
select fk_tco.table_schema || '.' || fk_tco.table_name as "TABLE", count(*) as foreign_keys, count(distinct pk_tco.table_name) as referenced_tables from information_schema.referential_constraints rco join information_schema.table_constraints fk_tco on rco.constraint_name = fk_tco.constraint_name and rco.constraint_schema = fk_tco.table_schema join information_schema.table_constraints pk_tco on rco.unique_constraint_name = pk_tco.constraint_name and rco.unique_constraint_schema = pk_tco.table_schema group by "TABLE" order by count(*) desc;
- table - table name preceded by schema name
- foreign_keys - number of references (FKs)
- referenced_tables - number of referenced tables. This may be other value than number of references, because multiple FKs can refer to one table
- One row represents one table
- Scope of rows: tables that reference other tables
- Ordered by number of foreign keys descending