Re: PATCH: logical_work_mem and logical streaming of large in-progress transactions

On Fri, Jul 10, 2020 at 3:37 PM Dilip Kumar <dilipbalaut@gmail.com> wrote:
>
> On Sat, Jul 4, 2020 at 11:35 AM Amit Kapila <amit.kapila16@gmail.com> wrote:
> >
> >
> > 8. We can't stream the transaction before we reach the
> > SNAPBUILD_CONSISTENT state because some other output plugin can apply
> > those changes unlike what we do with pgoutput plugin (which writes to
> > file). And, I think applying the transactions without reaching a
> > consistent state would be anyway wrong.  So, we should avoid that and
> > if do that then we should have an Assert for streamed txns rather than
> > sending abort for them in ReorderBufferForget.
>
> I was analyzing this point so currently, we only enable streaming in
> StartReplicationSlot so basically in CreateReplicationSlot the
> streaming will be always off because by that time plugins are not yet
> startup that will happen only on StartReplicationSlot.
>

What do you mean by 'startup' in the above sentence?  AFAICS, we do
call startup_cb_wrapper in CreateInitDecodingContext which is called
from both CreateReplicationSlot and create_logical_replication_slot
before the start of decoding.  In CreateInitDecodingContext, we call
StartupDecodingContext which should load the plugin.

-- 
With Regards,
Amit Kapila.
EnterpriseDB: http://www.enterprisedb.com