RE: Data is copied twice when specifying both child and parent table in publication

From: "wangw(dot)fnst(at)fujitsu(dot)com" <wangw(dot)fnst(at)fujitsu(dot)com>
To: "Takamichi Osumi (Fujitsu)" <osumi(dot)takamichi(at)fujitsu(dot)com>, Peter Smith <smithpb2250(at)gmail(dot)com>
Cc: Amit Kapila <amit(dot)kapila16(at)gmail(dot)com>, "shiy(dot)fnst(at)fujitsu(dot)com" <shiy(dot)fnst(at)fujitsu(dot)com>, "houzj(dot)fnst(at)fujitsu(dot)com" <houzj(dot)fnst(at)fujitsu(dot)com>, Amit Langote <amitlangote09(at)gmail(dot)com>, Peter Eisentraut <peter(dot)eisentraut(at)enterprisedb(dot)com>, "pgsql-hackers(at)lists(dot)postgresql(dot)org" <pgsql-hackers(at)lists(dot)postgresql(dot)org>, Dilip Kumar <dilipbalaut(at)gmail(dot)com>, Greg Nancarrow <gregn4422(at)gmail(dot)com>, vignesh C <vignesh21(at)gmail(dot)com>
Subject: RE: Data is copied twice when specifying both child and parent table in publication
Date: 2022-11-11 05:45:40
Message-ID: OS3PR01MB62752675082B2F1885D170639E009@OS3PR01MB6275.jpnprd01.prod.outlook.com
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On Tues, Nov 8, 2022 at 12:12 PM Osumi, Takamichi/大墨 昂道 <osumi(dot)takamichi(at)fujitsu(dot)com> wrote:
> On Monday, October 17, 2022 2:49 PM Wang, Wei/王 威
> <wangw(dot)fnst(at)fujitsu(dot)com> wrote:
> > Attach the new patch set.
> Hi, thank you for posting the new patches.
>
>
> Here are minor comments on the HEAD_v13-0002.

Thanks for your comments.

> (1) Suggestion for the document description
>
> + <para>
> + If a root partitioned table is published by any subscribed publications
> which
> + set publish_via_partition_root = true, changes on this root partitioned
> table
> + (or on its partitions) will be published using the identity and schema of this
> + root partitioned table rather than that of the individual partitions.
> + </para>
> +
>
> I suppose this sentence looks quite similar to the one in the previous paragraph
> and can be adjusted.
>
> IIUC the main value of the patch is to clarify what happens when
> we mix publications of different publish_via_partition_root settings for one
> partition hierarchy.
> If this is true, how about below sentence instead of the one above ?
>
> "
> There can be a case where a subscription combines publications with
> different publish_via_partition_root values for one same partition hierarchy
> (e.g. subscribe two publications indicating the root partitioned table and its child
> table respectively).
> In this case, the identity and schema of the root partitioned table take priority.
> "

Thanks for your suggestion.
I agree that we should mention that this description is for a case where one
subscription subscribes to multiple publications. And I think it would be
better if we mentioned that the option publish_via_partition_root is specified
on a publication that publishes a root partitioned table. So I added the
description of this case as you suggested.

> (2) Better documentation alignment
>
> I think we need to wrap publish_via_partition_root by "literal" tag
> in the documentation create_publication.sgml.

Improved.

The new patch set was attached in [1].

[1] - https://www.postgresql.org/message-id/OS3PR01MB6275FB5397C6A647F262A3A69E009%40OS3PR01MB6275.jpnprd01.prod.outlook.com

Regards,
Wang wei

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