Re: Parallel copy - Mailing list pgsql-hackers

From vignesh C
Subject Re: Parallel copy
Date
Msg-id CALDaNm0c4JGT5h6c+QcDKrD7M6894Hz_acU7y2y-xR3sLqq_qw@mail.gmail.com
Whole thread Raw
In response to Re: Parallel copy  (Ashutosh Sharma <ashu.coek88@gmail.com>)
List pgsql-hackers
On Mon, Sep 28, 2020 at 6:37 PM Ashutosh Sharma <ashu.coek88@gmail.com> wrote:
>
> On Mon, Sep 28, 2020 at 3:01 PM Amit Kapila <amit.kapila16@gmail.com> wrote:
> >
> > On Tue, Sep 22, 2020 at 2:44 PM vignesh C <vignesh21@gmail.com> wrote:
> > >
> > > Thanks Ashutosh for your comments.
> > >
> > > On Wed, Sep 16, 2020 at 6:36 PM Ashutosh Sharma <ashu.coek88@gmail.com> wrote:
> > > >
> > > > Hi Vignesh,
> > > >
> > > > I've spent some time today looking at your new set of patches and I've
> > > > some thoughts and queries which I would like to put here:
> > > >
> > > > Why are these not part of the shared cstate structure?
> > > >
> > > >     SerializeString(pcxt, PARALLEL_COPY_KEY_NULL_PRINT, cstate->null_print);
> > > >     SerializeString(pcxt, PARALLEL_COPY_KEY_DELIM, cstate->delim);
> > > >     SerializeString(pcxt, PARALLEL_COPY_KEY_QUOTE, cstate->quote);
> > > >     SerializeString(pcxt, PARALLEL_COPY_KEY_ESCAPE, cstate->escape);
> > > >
> > >
> > > I have used shared_cstate mainly to share the integer & bool data
> > > types from the leader to worker process. The above data types are of
> > > char* data type, I will not be able to use it like how I could do it
> > > for integer type. So I preferred to send these as separate keys to the
> > > worker. Thoughts?
> > >
> >
> > I think the way you have written will work but if we go with
> > Ashutosh's proposal it will look elegant and in the future, if we need
> > to share more strings as part of cstate structure then that would be
> > easier. You can probably refer to EstimateParamListSpace,
> > SerializeParamList, and RestoreParamList to see how we can share
> > different types of data in one key.
> >
>
> Yeah. And in addition to that it will also reduce the number of DSM
> keys that we need to maintain.
>

Thanks Ashutosh, This is handled as part of the v6 patch set.

Regards,
Vignesh
EnterpriseDB: http://www.enterprisedb.com



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