\set ECHO none
remove_provenance

(1 row)
city|which
Berlin|{Ellen,Susan}
New York|{John,Paul}
Paris|{Dave,Magdalen,Nancy}
(3 rows)
create_provenance_mapping

(1 row)
remove_provenance

(1 row)
city|which
Berlin|{Ellen_x,Ellen_y,Susan_x,Susan_y}
New York|{John_x,John_y,Paul_x,Paul_y}
Paris|{Dave_x,Dave_y,Magdalen_x,Magdalen_y,Nancy_x,Nancy_y}
(3 rows)
create_provenance_mapping

(1 row)
remove_provenance

(1 row)
city|which
Berlin|{Ellen,Susan}
New York|⊥
Paris|{Dave,Magdalen,Nancy}
(3 rows)