[DOCS] Bad return type in example

• postgresql-9.6-A4.pdf, page 891
  
• https://www.postgresql.org/docs/9.6/static/xfunc-sql.html#XFUNC-SQL-BASE-FUNCTIONS
  

Dear Doc Writers,

Would it not be better to change the return type of the following two sample functions to numeric ?

CREATE FUNCTION tf1 (accountno integer, debit numeric) RETURNS integer AS $$
    UPDATE bank
        SET balance = balance - debit
        WHERE accountno = tf1.accountno;
    SELECT balance FROM bank WHERE accountno = tf1.accountno;
$$ LANGUAGE SQL;

CREATE FUNCTION tf1 (accountno integer, debit numeric) RETURNS integer AS $$
    UPDATE bank
        SET balance = balance - debit
        WHERE accountno = tf1.accountno
    RETURNING balance;
$$ LANGUAGE SQL;

Since debit is of type numeric, balance is (probably) numeric too, so the function ought to return numeric. I guess that the function works as it is using implicit type cast.

With best regards,
Nikolaus Thiel