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

On Wed, Feb 5, 2020 at 4:05 PM Amit Kapila <amit(dot)kapila16(at)gmail(dot)com> wrote:
>
> On Wed, Feb 5, 2020 at 9:46 AM Dilip Kumar <dilipbalaut(at)gmail(dot)com> wrote:
> >
> > Fixed in the latest version sent upthread.
> >
>
> Okay, thanks. I haven't looked at the latest version of patch series
> as I was reviewing the previous version and I think all of these
> comments are in the patch which is not modified. Here are my
> comments:
>
> I think we don't need to maintain
> v8-0007-Support-logical_decoding_work_mem-set-from-create as per
> discussion in one of the above emails [1] as its usage is not clear.
>
> v8-0008-Add-support-for-streaming-to-built-in-replication
> 1.
> - information. The allowed options are <literal>slot_name</literal> and
> - <literal>synchronous_commit</literal>
> + information. The allowed options are <literal>slot_name</literal>,
> + <literal>synchronous_commit</literal>, <literal>work_mem</literal>
> + and <literal>streaming</literal>.
>
> As per the discussion above [1], I don't think we need work_mem here.
> You might want to remove the other usage from the patch as well.

After putting more thought on this it appears that there could be some
use cases for setting the work_mem from the subscription, Assume a
case where data are coming from two different origins and based on the
origin ids different slots might collect different type of changes,
So isn't it good to have different work_mem for different slots? I am
not saying that the current way of implementing is the best one but
that we can improve. First, we need to decide whether we have a use
case for this or not. Please let me know your thought on the same.

--
Regards,
Dilip Kumar
EnterpriseDB: http://www.enterprisedb.com