Re: is possible cache tupledesc templates in execution plan? significant performance issue, maybe bug?

On 2017-10-08 18:57:28 +0200, Pavel Stehule wrote:
> 2017-10-08 18:44 GMT+02:00 Andres Freund <andres(at)anarazel(dot)de>:
>
> > Hi,
> >
> > On 2017-10-08 18:36:23 +0200, Pavel Stehule wrote:
> > > 2. Lot of used tables are pretty wide - 60, 120, .. columns
> > >
> > > Now, I am doing profiling, and I see so most time is related to
> > >
> > > ExecTypeFromTLInternal(List *targetList, bool hasoid, bool skipjunk)
> >
> > Yea, that's known - I've complained about this a couple times. You could
> > try whether the following master branch helps:
> > https://git.postgresql.org/gitweb/?p=users/andresfreund/
> > postgres.git;a=shortlog;h=refs/heads/simple_statement_perf
> >
> > That's just micro-optimization though, not a more fundamental
> > solution. But for me it yields pretty nice speedups for cases with long
> > tlists.
> >
> >
> it is just this patch
>
> HeapTuple tup;
> Form_pg_type typTup;
>
> + if (typid < FirstBootstrapObjectId)
> + break;
> +
> tup = SearchSysCache1(TYPEOID, ObjectIdGetDatum(typid));
> if (!HeapTupleIsValid(tup))
> elog(ERROR, "cache lookup failed for type %u", typid);

No.