Re: PG_FREE_IF_COPY()

"John Hansen" <john(at)geeknet(dot)com(dot)au> writes:
> Given the following snippet:
> HeapTupleHeader tuple;
> Datum temp;
> bool isnull;

> tuple = PG_GETARG_HEAPTUPLEHEADER(0);
> temp = GetAttributeByName(tuple, "data", &isnull);

> When using this for a btree operator functions, you need to
> PG_FREE_IF_COPY(?,?);

> Which of the above parameters need I free?

It'd probably be wise to do a FREE_IF_COPY on the tuple.

GetAttributeByName, however, hasn't copied anything (if it's
a pass-by-ref type you'll just get a pointer into the tuple).
If you do a copy further down that might be a reason to free
something, but this code alone isn't making a copy.

regards, tom lane