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

On Tue, Sep 15, 2020 at 8:38 AM Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
>
> Amit Kapila <amit(dot)kapila16(at)gmail(dot)com> writes:
> > On Mon, Sep 14, 2020 at 9:42 PM Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
> >> BTW, unless someone has changed the behavior of dynahash when I
> >> wasn't looking, those MemoryContextSwitchTos shown above are useless.
>
> > As far as I can see they are useless in this case but I think they
> > might be required in case the user provides its own allocator function
> > (using HASH_ALLOC). So, we can probably remove those from here?
>
> You could imagine writing a HASH_ALLOC allocator whose behavior
> varies depending on CurrentMemoryContext, but it seems like a
> pretty foolish/fragile way to do it. In any case I can think of,
> the hash table lives in one specific context and you really
> really do not want parts of it spread across other contexts.
> dynahash.c is not going to look kindly on pieces of what it
> is managing disappearing from under it.
>

I agree that doesn't make sense. I have fixed all the comments
discussed in the attached patch.

--
With Regards,
Amit Kapila.