Re: Packed short varlenas, what next?

Peter Eisentraut <peter_e(at)gmx(dot)net> writes:
> As I has mentioned earlier, I'm missing a plan to allow 8-byte varlena
> sizes.

I don't think it's entirely fair to expect this patch to solve that
problem. In the first place, that is not what the patch's goal is,
but merely tangentially related to the same code. In the second place,
I don't see any way we could possibly do that without wide-ranging code
changes; to take just one point, much of the code that works with
varlenas uses "int" or "int32" variables to compute sizes. So it would
certainly expand the scope of the patch quite a lot to try to put that
in place, and it's mighty late in the devel cycle to be thinking about
that sort of thing.

For the moment I think it should be enough to expect that the patch
allow for more than one format of TOAST pointer, so that if we ever did
try to support 8-byte varlenas, there'd be a way to represent them
on-disk. Some of the alternatives that we discussed last year used up
all of the "prefix space" and wouldn't have allowed expansion in this
particular direction.

regards, tom lane