Re: why there is not VACUUM FULL CONCURRENTLY?

Junwang Zhao <zhjwpku(at)gmail(dot)com> wrote:

> + if (TransactionIdIsNormal(HeapTupleHeaderGetRawXmax(tuple->t_data)) &&
> + HeapTupleMVCCNotDeleted(tuple, snapshot, buffer))
> + {
> + /* TODO More work needed here?*/
> + tuple->t_data->t_infomask |= HEAP_XMAX_INVALID;
> + HeapTupleHeaderSetXmax(tuple->t_data, 0);
> + }
>
> I don't quite understand the above code, IIUC xmax and xmax invalid
> are set directly on the buffer page. What if the command failed? Will
> this break the visibility rules?

Oh, that's too bad. Of course, the tuple must be copied. Fixed in the next
version. Thanks!

(0009- added to get some debugging information from the cfbot. It fails
sometimes and I'm not able to reproduce the errors.)

--
Antonin Houska
Web: https://www.cybertec-postgresql.com