Re: tuptoaster.c must *not* use SnapshotAny

Tom Lane wrote:
> 
> Hiroshi Inoue <Inoue@tpf.co.jp> writes:
> 
> > For example is it possible to update a toast
> > chunk partially using SnapshotToast ?
> 
> As things stand (with either SnapshotToast or the old SnapshotAny way)
> it is never possible to update an individual toast value, either
> partially or wholly.  All you can do is lay down a new toast value (with
> a new identifying OID) and then delete the old one.
> 
> But I'm not sure that this is wrong, or fixable.  Trying to update part
> of a toasted value is very much like wanting to update part of an
> existing row in-place, which we cannot possibly do.

Bytea seems to be considered as a candidate for BLOB
though I think the entirely new type is preferable.
It seems impossible to implement a functionality like
inv_write using bytea which the current large object
stuff has.

regards,
Hiroshi Inoue