Gaetano, > I do not consider my design as "unsafe", this is for example how a > cache works: expose a "read" without side effect but updating internal > statistics. After all the read will not alter the data that it expose > but other data that the user even don't know the existence.
At issue is the working definitions of the function states (and yes, I know these aren't the formal definitions but these are what is useful): IMMUTABLE: result of function will always be the same given the same inputs; STABLE: result of function will be the same for the duration of the transaction. VOLATILE: you can't count on any particular result based on the inputs Any function involving an UPDATE -- and I write a LOT of them -- clearly falls into the last group. You never know what you're going to get as a result of an UPDATE; you could get an index violation, a lock wait, a deadlock, a constraint violation, etc. -- Josh Berkus Aglio Database Solutions San Francisco ---------------------------(end of broadcast)--------------------------- TIP 2: you can get off all lists at once with the unregister command (send "unregister YourEmailAddressHere" to [EMAIL PROTECTED])