Re: ModifyTable overheads in generic plans

Hello,

On Fri, Aug 7, 2020 at 9:26 PM Amit Langote <amitlangote09@gmail.com> wrote:
> On Tue, Aug 4, 2020 at 3:15 PM Amit Langote <amitlangote09@gmail.com> wrote:
> > On Sat, Aug 1, 2020 at 4:46 AM Robert Haas <robertmhaas@gmail.com> wrote:
> > > On Fri, Jun 26, 2020 at 8:36 AM Amit Langote <amitlangote09@gmail.com> wrote:
> > > > 0001 and 0002 are preparatory patches.
> > >
> > > I read through these patches a bit but it's really unclear what the
> > > point of them is. I think they need better commit messages, or better
> > > comments, or both.
> >
> > Thanks for taking a look.  Sorry about the lack of good commentary,
> > which I have tried to address in the attached updated version. I
> > extracted one more part as preparatory from the earlier 0003 patch, so
> > there are 4 patches now.
> >
> > Also as discussed with Daniel, I have changed the patches so that they
> > can be applied on plain HEAD instead of having to first apply the
> > patches at [1].  Without runtime pruning for UPDATE/DELETE proposed in
> > [1], optimizing ResultRelInfo creation by itself does not improve the
> > performance/scalability by that much, but the benefit of lazily
> > creating ResultRelInfos seems clear so I think maybe it's okay to
> > pursue this independently.
>
> Per cfbot's automatic patch tester, there were some issues in the 0004 patch:
>
> nodeModifyTable.c: In function ‘ExecModifyTable’:
> 1529nodeModifyTable.c:2484:24: error: ‘junkfilter’ may be used
> uninitialized in this function [-Werror=maybe-uninitialized]
> 1530              junkfilter->jf_junkAttNo,
> 1531                        ^
> 1532nodeModifyTable.c:2309:14: note: ‘junkfilter’ was declared here
> 1533  JunkFilter *junkfilter;
> 1534              ^
> 1535cc1: all warnings being treated as errors
> 1536<builtin>: recipe for target 'nodeModifyTable.o' failed
> 1537make[3]: *** [nodeModifyTable.o] Error 1
>
> Fixed in the attached updated version

Needed a rebase due to f481d28232.  Attached updated patches.

-- 
Amit Langote
EnterpriseDB: http://www.enterprisedb.com