Re: cursors question

Oscar Goldes wrote: > > Hello,=20 > a simple question about cursors in informix online 7.2 > using powerbuilder as client. > > If a stored procedure uses an implicit cursor such as > foreach > select ...... > return.... with resume > end foreach> > The client uses a corresponding loop to fetch results. > > My (very simple) question is: > > When the procedure is executed, how are the results handled, i.e: > are they sent to the client at once in a single operation, stored > there somewhere, and retrieved localy by the fetch loop in the > application? in this case, where are they stored? > are they kept on the server and returned to the client on each > (client) fetch iteration? in this case, where are they kept? > is each iteration in the foreach executed only as the client executes > a fetch? Oscar, as I recall it, the engine fetches each row in a procedure as it would in in a regular query - a single row is returned to the user as a time. (If the user asks for bufferloads for a scroll cursor, the engine fetches more in order ot fill the buffer.) As the user repeatedly executes the FETCH command, the engine itself fetches another row and sends it to the user. (Corrections requested on the following point:) The engine does not store rows before sending to the user; it worries about stale data and the locking business. This is the behavior in both ordinary queries and stored procedures. -- -- Jake (In pursuit of undomesticated aquatic avians) +-----------------------------------------------------------+ | Impeccable Logic: A thought process which successfully | | resists chicken bites | +-----------------------------------------------------------+