Hi Roberto I'll try to be more clear, please read carefully before answering
I know what a deterministic expression is - but what kinds of output must be deterministic for a procedure to be defined as DETERMINISTIC? There are many types of output for a proc: * OUT params * SELECTs * writes on tables * SET @var For a deterministic proc, do all of these need to be deterministic? I guess the answer isn't easy. -- For "NO SQL" a complete list of SQL statements would be needed. If we use this as a reference: http://dev.mysql.com/doc/refman/5.6/en/sql-syntax.html , even RETURN seems to be a SQL statement, but of course it can't be true, because it's impossible to write a func without RETURN. Greetings Federico -------------------------------------------- Lun 2/9/13, Roberto Spadim <[email protected]> ha scritto: Oggetto: Re: [Maria-discuss] CREATE PROCEDURE clauses A: "Federico Razzoli" <[email protected]> Cc: "Mailing-List mariadb" <[email protected]> Data: Lunedì 2 settembre 2013, 15:23 Hi Federico! 2013/9/2 Federico Razzoli <[email protected]>: > 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? i think it's something like: RANDON() = not deterministic, ROUND(1.5) = deterministic maybe it's important for replication (must be done via binary, instead SQL), and it's important for query cache (not deterministic can't be cached) > * 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; > > But what is a "no sql" procedure (if such a procedure even exists)? i don't know, but reading mysql protocol, there's some functions for show fields, process info, process kill, http://dev.mysql.com/doc/internals/en/text-protocol.html > 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. > > Greetings > Federico > > _______________________________________________ > Mailing list: https://launchpad.net/~maria-discuss > Post to : [email protected] > Unsubscribe : https://launchpad.net/~maria-discuss > More help : https://help.launchpad.net/ListHelp -- Roberto Spadim SPAEmpresarial _______________________________________________ Mailing list: https://launchpad.net/~maria-discuss Post to : [email protected] Unsubscribe : https://launchpad.net/~maria-discuss More help : https://help.launchpad.net/ListHelp
