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WITH fk as (select
(select nspname from pg_namespace where oid=f.relnamespace) as foreign_schema,
f.relname as foreign_table,
f.oid as foreign_table_oid,
o.confkey AS foreign_col,
(select nspname from pg_namespace where oid=c.relnamespace) as target_schema,
c.relname as target_table,
c.oid as target_table_oid,
o.conkey AS target_col
from pg_constraint o inner join pg_class c on c.oid = o.conrelid
inner join pg_class f on f.oid = o.confrelid
where o.contype = 'f'),
fk_unnest as (select foreign_schema, foreign_table,  foreign_table_oid, foreign_col, foreign_col_num, target_schema, target_table, target_table_oid, target_col, target_col_num, ordin
from fk, unnest(fk.foreign_col, fk. target_col) with ordinality as f(foreign_col_num, target_col_num, ordin)),
fk_with_names as (select foreign_schema, foreign_table, a_foreign.attname as foreign_col, target_schema, target_table, a_target.attname as target_col
from fk_unnest fk inner join pg_attribute a_foreign on fk.foreign_col_num = a_foreign.attnum and fk.foreign_table_oid = a_foreign.attrelid and a_foreign.attisdropped = false
inner join pg_attribute a_target on fk.target_col_num = a_target.attnum and fk.target_table_oid = a_target.attrelid and a_target.attisdropped = false)
SELECT foreign_schema, foreign_table, foreign_col, Count(DISTINCT target_col) AS nr_of_different_ref_names,
string_agg(DISTINCT target_col, ';
' ORDER BY target_col) AS different_column_names,
string_agg(target_schema || '.' || target_table || '.' || target_col,';
' ORDER BY target_schema, target_table, target_col) AS referencing_cols
FROM fk_with_names
GROUP BY foreign_schema, foreign_table, foreign_col
HAVING Count(DISTINCT target_col)>1
ORDER BY Count(DISTINCT target_col) DESC, foreign_schema, foreign_table, foreign_col;