SQL question

Hello,

I'm a French user of MonetDB, and I have a SQL question, I want to execute on MonetDB equivalent of this mysql request, and i don't find any solution :

"SELECT field1, field2 FROM table GROUP BY field3 LIMIT 5;"

I want to do a GROUP BY of a field3 which is not in the SELECT to get a limit of request results by this field3, like the "first" function of some databases.

Does anyone have any idea on how I can do that ?

Thanks for your help,

Remi