Horton

Re: Parallel copy

vignesh C <vignesh21@gmail.com>

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From: vignesh C <vignesh21@gmail.com>
To: Ashutosh Sharma <ashu.coek88@gmail.com>
Cc: Amit Kapila <amit.kapila16@gmail.com>, "Hou, Zhijie" <houzj.fnst@cn.fujitsu.com>, Bharath Rupireddy <bharath.rupireddyforpostgres@gmail.com>, Rafia Sabih <rafia.pghackers@gmail.com>, Andres Freund <andres@anarazel.de>, Robert Haas <robertmhaas@gmail.com>, Ants Aasma <ants@cybertec.at>, Tomas Vondra <tomas.vondra@2ndquadrant.com>, Alastair Turner <minion@decodable.me>, Thomas Munro <thomas.munro@gmail.com>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Date: 2020-10-27T15:37:02Z
Lists: pgsql-hackers

Commits

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  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 Fri, Oct 23, 2020 at 6:58 PM Ashutosh Sharma <ashu.coek88@gmail.com> wrote:
>
> >
> > I think, if possible, all these if-else checks in CopyFrom() can be
> > moved to a single function which can probably be named as
> > IdentifyCopyInsertMethod() and this function can be called in
> > IsParallelCopyAllowed(). This will ensure that in case of Parallel
> > Copy when the leader has performed all these checks, the worker won't
> > do it again. I also feel that it will make the code look a bit
> > cleaner.
> >
>
> Just rewriting above comment to make it a bit more clear:
>
> I think, if possible, all these if-else checks in CopyFrom() should be
> moved to a separate function which can probably be named as
> IdentifyCopyInsertMethod() and this function called from
> IsParallelCopyAllowed() and CopyFrom() functions. It will only be
> called from CopyFrom() when IsParallelCopy() returns false. This will
> ensure that in case of Parallel Copy if the leader has performed all
> these checks, the worker won't do it again. I also feel that having a
> separate function containing all these checks will make the code look
> a bit cleaner.
>

In the recent patch posted we have changed it to simplify the check
for parallel copy, it is not an exact match. I feel this comment is
not applicable on the latest patch

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