Horton

Re: Parallel copy

Ashutosh Sharma <ashu.coek88@gmail.com>

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From: Ashutosh Sharma <ashu.coek88@gmail.com>
To: Amit Kapila <amit.kapila16@gmail.com>
Cc: vignesh C <vignesh21@gmail.com>, Greg Nancarrow <gregn4422@gmail.com>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>, Bharath Rupireddy <bharath.rupireddyforpostgres@gmail.com>
Date: 2020-09-28T13:06:47Z
Lists: pgsql-hackers

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →

  1. Allow WaitLatch() to be used without a latch.

  2. Add %P to log_line_prefix for parallel group leader

  3. Include replication origins in SQL functions for commit timestamp

  4. Avoid useless buffer allocations during binary COPY FROM.

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.

-- 
With Regards,
Ashutosh Sharma
EnterpriseDB:http://www.enterprisedb.com