DOCS - clarify CREATE SUBSCRIPTION only synchronizes sequences when copy_data=true
While reviewing another patch I referred to the information of "29.7.
Replicating Sequences #" [1]https://www.postgresql.org/docs/19/logical-replication-sequences.html which says:
"use CREATE SUBSCRIPTION to initially synchronize the published sequences."
AFAIK, that is not entirely correct -- synchronisation of sequences
happens only when the "copy_data" option is true. Although copy_data
default is true, the original text was misleading. Anyway, it misled
me.
PSA a patch to clarify that "copy_data = true" is needed.
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[1]: https://www.postgresql.org/docs/19/logical-replication-sequences.html
Kind Regards,
Peter Smith.
Fujitsu Australia
Attachments:
v1-0001-DOCS-clarify-copy_data-is-needed-to-synchronise-s.patchapplication/octet-stream; name=v1-0001-DOCS-clarify-copy_data-is-needed-to-synchronise-s.patchDownload+3-3
On Thu, 25 Jun 2026 at 06:22, Peter Smith <smithpb2250@gmail.com> wrote:
While reviewing another patch I referred to the information of "29.7.
Replicating Sequences #" [1] which says:
"use CREATE SUBSCRIPTION to initially synchronize the published sequences."AFAIK, that is not entirely correct -- synchronisation of sequences
happens only when the "copy_data" option is true. Although copy_data
default is true, the original text was misleading. Anyway, it misled
me.PSA a patch to clarify that "copy_data = true" is needed.
Let's include this to avoid confusion.
Few comments:
1) There should be a space after </link>:
+ use <link linkend="sql-createsubscription-params-with-copy-data">
+ <command>CREATE SUBSCRIPTION ... WITH (copy_data = true)</command>
+ </link>to initially synchronize the published sequences.
2) copy_data = true is the default, so it may mislead users into
thinking they must explicitly specify it. How about changing it to:
use CREATE SUBSCRIPTION with the default copy_data = true behavior to
initially synchronize the published sequences.
Regards,
Vignesh
Hi Vignesh.
Thanks for reviewing!
PSA v2 worded slightly differently to mention the copy_data default.
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Kind Regards,
Peter Smith.
Fujitsu Australia
Attachments:
v2-0001-DOCS-clarify-copy_data-is-needed-to-synchronise-s.patchapplication/octet-stream; name=v2-0001-DOCS-clarify-copy_data-is-needed-to-synchronise-s.patchDownload+3-2
Thanks for the updated version. This version looks good to me.
Regards,
Vignesh
Show quoted text
On Fri, 26 Jun 2026 at 04:20, Peter Smith <smithpb2250@gmail.com> wrote:
Hi Vignesh.
Thanks for reviewing!
PSA v2 worded slightly differently to mention the copy_data default.
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Kind Regards,
Peter Smith.
Fujitsu Australia
This docs patch was combined with a similar one and has now been pushed [1]/messages/by-id/E1wheve-000Epy-38@gemulon.postgresql.org.
I have closed the CF entry.
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[1]: /messages/by-id/E1wheve-000Epy-38@gemulon.postgresql.org
Kind Regards
Peter Smith.
Fujitsu Australia