Re: Faster inserts with mostly-monotonically increasing values

On Sun, Mar 25, 2018 at 6:00 AM, Andrew Dunstan <
andrew(dot)dunstan(at)2ndquadrant(dot)com> wrote:

> On Fri, Mar 23, 2018 at 8:27 PM, Pavan Deolasee
> <pavan(dot)deolasee(at)gmail(dot)com> wrote:
> >>
> >>
> >> I would probably just have a few regression lines that should be sure
> >> to exercise the code path and leave it at that.
> >>
> >
> > I changed the regression tests to include a few more scenarios, basically
> > using multi-column indexes in different ways and they querying rows by
> > ordering rows in different ways. I did not take away the vacuum and I
> > believe it will actually help the tests by introducing some fuzziness in
> the
> > tests i.e. if the vacuum does not do its job, we might execute a
> different
> > plan and ensure that the output remains unchanged.
> >
>
>
> If we're going to keep the vacuums in there, do we need to add a wait
> barrier like Claudio suggested upthread?
>
>
I don't think we need the wait barrier since we're no longer printing the
explain plan. In the worst case, the vacuum may not get to set pages
all-visible, thus planner choosing something other than an index-only-scan,
but I guess that fuzziness actually helps the regression tests. That way we
get confirmation regarding the final result irrespective of the plan
chosen.

Thanks,
Pavan

--
Pavan Deolasee http://www.2ndQuadrant.com/
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