maria-discuss team mailing list archive

[Federico Razzoli <federico_raz@xxxxxxxx>]

Thank you! I wrote these info in the KB
https://mariadb.com/kb/en/create-procedure/
https://mariadb.com/kb/en/create-function/

Federico


--------------------------------------------
Mar 3/9/13, Sergei Golubchik <serg@xxxxxxxxxxx> ha scritto:

 Oggetto: Re: [Maria-discuss] CREATE PROCEDURE clauses
 A: "Federico Razzoli" <federico_raz@xxxxxxxx>
 Cc: "Mailing-List mariadb" <maria-discuss@xxxxxxxxxxxxxxxxxxx>
 Data: Martedì 3 settembre 2013, 09:13
 
 Hi, Federico!
 
 On Sep 02, Federico Razzoli wrote:
 > Ciao,
 > 
 > I wanted to add some info in the CREATE PROCEDURE page
 in the KB, but
 > I think that some info about CREATE PROCEDURE clauses
 miss both in the
 > kb and in the MySQL manual.
 > 
 > * [NOT] DETERMINISTIC. From MySQL docs:
 > "A routine is considered “deterministic” if it
 always produces the
 > same result for the same input parameters, and “not
 deterministic”
 > otherwise."
 > What does this exactly mean for procedures? OUT and
 INOUT parameters?
 > Resultsets returned by the procedure? Both?
 
 It doesn't really matter.
 
 For stored functions, optimizer uses the value of [NOT]
 DETERMINISTIC to
 optimize function calls.
 
 But for procedures it's not used for anything, as far as I
 know.
 
 > * NO SQL: As far as I understand, even SET is a SQL
 statement. I guess
 > that a "no sql" function is something like 
 > CREATE FUNCTION x(n INT) RETURNS INT
 > BEGIN
 > RETURN n*2;
 > END;
 
 Not quite.
 As far as I understand,
 "NO SQL" means that there's no SQL in the routine *at all*.
 Like,it might be written on C or ADA or whatever sql
 standard specifies:
 
 <language clause> ::= LANGUAGE <language name>
 <language name> ::=
     ADA
   | C
   | COBOL
   | FORTRAN
   | M | MUMPS
   | PASCAL
   | PLI
   | SQL
 
 It's particularly important if a routine has the EXTERNAL
 clause,
 instead of the BEGIN ... END body.
 
 But MariaDB does not support EXTERNAL or any other LANGUAGE
 besides SQL.
 
 > I'm sorry if this info is already written somewhere,
 but I really
 > wasn't able to find it - and I feel that the KB should
 specify things
 > like these.
 
 It's only on the SQL-99 Complete, Really pages:
 
 https://mariadb.com/kb/en/create-procedurefunctionmethod-statement/#language-subclause
 https://mariadb.com/kb/en/create-procedurefunctionmethod-statement/#sql-data-access-indication-subclause
 
 Regards,
 Sergei