Re: WIP: Access method extendability

Code looks much better now, thanks. Still I believe it could be improved.

I don't think that using srand() / rand() in signValue procedure the
way you did is such a good idea. You create a side affect (changing
current randseed) which could cause problems in some cases. And there
is no real need for that. For instance you could use following formula
instead:

hash(attno || hashVal || j)

And a few more things.

> +     memset(opaque, 0, sizeof(BloomPageOpaqueData));
> +     opaque->maxoff = 0;

This looks a bit redundant.

> + for (my $i = 1; $i <= 10; $i++)

More idiomatic Perl would be `for my $i (1..10)`.

> +                     UnlockReleaseBuffer(buffer);
> +                     ReleaseBuffer(metaBuffer);
> +                     goto away;

In general I don't have anything against goto. But are you sure that
using it here is really justified?