Re: Problems with the varlena patch in my module

On Saturday 07 April 2007 04:08:34 Tom Lane wrote:
> Tzahi Fadida <Tzahi(dot)ML(at)gmail(dot)com> writes:
> > This is an excerpt from my code:
> > newtset->tids = (bytea *) fastgetattr(tupleTSet, LABELS_ALIGNED,
> > fctx->tupleSetDesc, &isnull);
> >
> > It seems that for an empty bytea (only the size of the header), i get
> > that VARSIZE(newtset->tids)==534765440
> > instead of VARHDRSZ.
>
> That code has always been broken, you just failed to exercise the

It always worked before the patch so it was hard to know that.
You see, i knew from the start that this attribute would never reach certain
sizes so i never thought it would be toasted.

> problem before. There needs to be a detoasting call there, not
> merely a cast. DatumGetByteaP() would probably be appropriate.

Thanks. One more question though, what is the CATALOG_VERSION_NO
of the varlena patch?

The second problem i have (it is a bit long but simple so please bear with
me):
You see, before there were slots (at least stable working slots)
tuples (slot_getattr, etc...), i needed this functionality.
So, i created the following function (which broke because of the varlena patch
on the att_align function):
bool
heap_deformtuple_iterative(HeapTuple tuple,
                                                   TupleDesc tupleDesc,
                                                   Datum *values,
                                                   char *nulls,
deformTupleIterativeState * ds,
                                                   int tillAttNum, bool
finishAll)

Where tuple is tuple,
tupleDesc is of course TupleDesc.
values are to store the deformed values (the array is already allocated).
nulls, same.
ds is a pointer to a structure i made to save the state of the
heap_deformtuple in mid work.
tillAttNum is a number of attributes from the start to deform up to.
finishAll - deform all the remaining attributes.

Now, i want to move to the more standard way to do this. However, i want to
keep the structure where i have a tuple->t (the tuple), tuple->v (the values
array), tuple->n (the nulls array). I keep many tuples in memory like this
and i can't change this now. I want to keep in memory only the heaptuple
tuple->t and the deformed arrays tuple->v, tuple->n and possibly another
needed (such as ds) structure for as long as the tuple is not completely
deformed.

What do you recommend (aside from me reimplementing the heap_deformtuple
iterative again hoping it won't break again)?

--
Regards,
        Tzahi.
--
Tzahi Fadida
Blog: http://tzahi.blogsite.org | Home Site: http://tzahi.webhop.info
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