class ActiveRecord::ConnectionAdapters::PostgreSQL::Table

def remove_unique_constraint(...)

See {connection.remove_unique_constraint}[rdoc-ref:SchemaStatements#remove_unique_constraint]

t.remove_unique_constraint(name: "unique_position")

Removes the given unique constraint from the table.
def remove_unique_constraint(...)
  @base.remove_unique_constraint(name, ...)
end