Re: Faster inserts with mostly-monotonically increasing values

On Mon, Mar 26, 2018 at 6:06 PM, Pavan Deolasee
<pavan(dot)deolasee(at)gmail(dot)com> wrote:
>
>
> 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.
>

Fair enough. Committed.

cheers

andrew

--
Andrew Dunstan https://www.2ndQuadrant.com
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services