Re: COPY and Volatile default expressions

On 16.04.2013 14:38, Simon Riggs wrote:
> On 15 April 2013 21:53, Simon Riggs<simon(at)2ndquadrant(dot)com> wrote:
>
>> So I'll treat this as two separate cases:
>> * add special case for sequences
>
> Patch attached.
>
> + if (IsA(node, FuncExpr))
> + {
> + FuncExpr *expr = (FuncExpr *) node;
> +
> + /*
> + * For this case only, we want to ignore the volatility of the
> + * nextval() function, since some callers want this. nextval()
> + * has no other args other than sequence name, so we can just
> + * return false immediately in this case.
> + */
> + if (expr->funcid == F_NEXTVAL_OID)
> + return false;
> + else if (func_volatile(expr->funcid) == PROVOLATILE_VOLATILE)
> + return true;
> + /* else fall through to check args */
> + } ...

You still need to check the args, if the function is nextval, otherwise
you incorrectly perform the optimization for something like
"nextval(myvolatilefunc())".

- Heikki