Re: [HACKERS] [PATCH] Generic type subscripting

> On 30 January 2018 at 16:47, Dmitry Dolgov <9erthalion6(at)gmail(dot)com> wrote:
> > On 29 January 2018 at 14:41, Arthur Zakirov <a(dot)zakirov(at)postgrespro(dot)ru>
wrote:
> >
> > I have a few comments.
>
> Thanks for suggestions, I've incorporated all of them in a new version of
the
> patch.

Few more updates. I've attached a new version with some minor changes,
mostly
about moving a subscripting depth check to type related logic. Also I've
made
some performance tests for arrays using pgbench:

pgbench -c 10 -j 2 -T 600 -f test.sql -r

with queries like:

select (ARRAY[1, 2, 3])[0];
select (ARRAY[1, 2, 3, ..., 98, 99, 100])[0];
select (ARRAY[[[[[[1]]]]]])[1][1][1][1][1][1];
select (ARRAY[[[[[[1, 2, 3]]]]]])[1][1][1][1][1:2];

and the difference in average latency was about 2%:

* with the patch

number of transactions actually processed: 349211
latency average = 1.718 ms
tps = 5820.048783 (including connections establishing)
tps = 5820.264433 (excluding connections establishing)

* without the patch

number of transactions actually processed: 356024
latency average = 1.685 ms
tps = 5933.538195 (including connections establishing)
tps = 5934.124599 (excluding connections establishing)