Re: Gather Merge

I am sorry for the delay, here is the latest re-based patch.

my colleague Neha Sharma, reported one regression with the patch, where
explain output for the Sort node under GatherMerge was always showing
cost as zero:

explain analyze select '' AS "xxx" from pgbench_accounts where filler like
'%foo%' order by aid;
QUERY
PLAN
------------------------------------------------------------------------------------------------------------------------------------------------
Gather Merge (cost=47169.81..70839.91 rows=197688 width=36) (actual
time=406.297..653.572 rows=200000 loops=1)
Workers Planned: 4
Workers Launched: 4
-> Sort (*cost=0.00..0.00 rows=0 width=0*) (actual
time=368.945..391.124 rows=40000 loops=5)
Sort Key: aid
Sort Method: quicksort Memory: 3423kB
-> Parallel Seq Scan on pgbench_accounts (cost=0.00..42316.60
rows=49422 width=36) (actual time=296.612..338.873 rows=40000 loops=5)
Filter: (filler ~~ '%foo%'::text)
Rows Removed by Filter: 360000
Planning time: 0.184 ms
Execution time: 734.963 ms

This patch also fix that issue.

On Wed, Feb 1, 2017 at 11:27 AM, Michael Paquier <michael(dot)paquier(at)gmail(dot)com>
wrote:

> On Mon, Jan 23, 2017 at 6:51 PM, Kuntal Ghosh
> <kuntalghosh(dot)2007(at)gmail(dot)com> wrote:
> > On Wed, Jan 18, 2017 at 11:31 AM, Rushabh Lathia
> > <rushabh(dot)lathia(at)gmail(dot)com> wrote:
> >>
> > The patch needs a rebase after the commit 69f4b9c85f168ae006929eec4.
>
> Is an update going to be provided? I have moved this patch to next CF
> with "waiting on author" as status.
> --
> Michael
>

--
Rushabh Lathia