Re: Columns correlation and adaptive query optimization

On Fri, Mar 19, 2021 at 10:28 PM Konstantin Knizhnik
<k(dot)knizhnik(at)postgrespro(dot)ru> wrote:
>
>
>
> On 19.03.2021 12:17, Yugo NAGATA wrote:
> > On Wed, 10 Mar 2021 03:00:25 +0100
> > Tomas Vondra <tomas(dot)vondra(at)enterprisedb(dot)com> wrote:
> >
> >> What is being proposed here - an extension suggesting which statistics
> >> to create (and possibly creating them automatically) is certainly
> >> useful, but I'm not sure I'd call it "adaptive query optimization". I
> >> think "adaptive" means the extension directly modifies the estimates
> >> based on past executions. So I propose calling it maybe "statistics
> >> advisor" or something like that.
> > I am also agree with the idea to implement this feature as a new
> > extension for statistics advisor.
> >
> >> BTW Why is "qual" in
> >>
> >> static void
> >> AddMultiColumnStatisticsForQual(void* qual, ExplainState *es)
> >>
> >> declared as "void *"? Shouldn't that be "List *"?
> > When I tested this extension using TPC-H queries, it raised segmentation
> > fault in this function. I think the cause would be around this argument.
> >
> > Regards,
> > Yugo Nagata
> >
> Attached please find new version of the patch with
> AddMultiColumnStatisticsForQual parameter type fix and one more fix
> related with handling synthetic attributes.
> I can not reproduce the crash on TPC-H queries, so if the problem
> persists, can you please send me stack trace and may be some other
> information helping to understand the reason of SIGSEGV?
>

"C:\projects\postgresql\pgsql.sln" (default target) (1) ->
"C:\projects\postgresql\auto_explain.vcxproj" (default target) (45) ->
(ClCompile target) ->
contrib/auto_explain/auto_explain.c(658): error C2039: 'mt_plans' : is
not a member of 'ModifyTableState'
[C:\projects\postgresql\auto_explain.vcxproj]
contrib/auto_explain/auto_explain.c(659): error C2039: 'mt_nplans' :
is not a member of 'ModifyTableState'
[C:\projects\postgresql\auto_explain.vcxproj]
contrib/auto_explain/auto_explain.c(660): error C2198:
'AddMultiColumnStatisticsForMemberNodes' : too few arguments for call
[C:\projects\postgresql\auto_explain.vcxproj]
2 Warning(s)
3 Error(s)

Also Yugo Nagata's comments need to be addressed, I'm changing the
status to "Waiting for Author".

Regards,
Vignesh