Re: Replication slot stats misgivings

On Wed, Apr 28, 2021 at 6:39 PM Amit Kapila <amit(dot)kapila16(at)gmail(dot)com> wrote:
>
> On Wed, Apr 28, 2021 at 12:49 PM Masahiko Sawada <sawada(dot)mshk(at)gmail(dot)com> wrote:
> >
> >
> > BTW regarding the commit f5fc2f5b23 that added total_txns and
> > total_bytes, we add the reorder buffer size (i.g., rb->size) to
> > rb->totalBytes but I think we should use the transaction size (i.g.,
> > txn->size) instead:
> >
>
> You are right about the problem but I think your proposed fix also
> won't work because txn->size always has current transaction size which
> will be top-transaction in the case when a transaction has multiple
> subtransactions. It won't include the subtxn->size.

Right. I missed the point that ReorderBufferProcessTXN() processes
also subtransactions.

> I think we can fix it by keeping track of total_size in toptxn as we
> are doing for the streaming case in ReorderBufferChangeMemoryUpdate.
> We can probably do it for non-streaming cases as well.

Agreed.

I've updated the patch. What do you think?

Regards,

--
Masahiko Sawada
EDB: https://www.enterprisedb.com/