Re: Gather Merge

On Thu, Feb 2, 2017 at 2:32 AM, Rushabh Lathia <rushabh(dot)lathia(at)gmail(dot)com> wrote:
> Please find attached latest patch.

The latest patch still applies (with some fuzz), builds and the
regression tests pass.

I see that Robert made a number of changes and posted a v6 along with
some numbers which he described as lacklustre, but then fixed a row
estimate problem which was discouraging parallel joins (commit
0c2070ce). Rushabh posted a v7 and test results which look good. As
far as I can see there are no outstanding issues or unhandled review
feedback. I've had a fresh read through of the latest version and
have no further comments myself.

I've set this to ready-for-committer now. If I've misunderstood and
there are still unresolved issues from that earlier email exchange or
someone else wants to post a review or objection, then of course
please feel free to set it back.

BTW There is no regression test supplied. I see that commit 5262f7a4
adding parallel index scans put simple explain output in
"select_parallel" to demonstrate the new kind of plan being created;
perhaps this patch should do the same? I know it wouldn't really test
much of the code but it's at least something. Perhaps you could post
a new version with that?

--
Thomas Munro
http://www.enterprisedb.com