Thread: 13 25.1.1 clarify "The dumps produced by pg_dump are relative to template0"
13 25.1.1 clarify "The dumps produced by pg_dump are relative to template0"
From
PG Doc comments form
Date:
The following documentation comment has been logged on the website: Page: https://www.postgresql.org/docs/13/backup-dump.html Description: In doc version 13 section 25.1.1 it reads, "The dumps produced by pg_dump are relative to template0. This means that any languages, procedures, etc. added via template1 will also be dumped by pg_dump. As a result, when restoring, if you are using a customized template1, you must create the empty database from template0, as in the example above." Unless one knows that template0 and template1 start off identical the wording above is confusing because it doesn't make sense why a modified template1 would necessitate ensuring creation from template0. I think a much clearer wording would be, "In a new cluster template0 and template1 are identical. Additionally, template1 is the source for all CREATE DATABASE commands. Dumps produced by pg_dump, however, are relative to template0. This means that any languages, procedures, etc. added via template1 will also be dumped by pg_dump. As a result, when restoring, if you are using a customized template1, you must create the empty database from template0, as in the example above." Additionally, there is some wording above that is similarly confusing: "The database dbname will not be created by this command, so you must create it yourself from template0 before executing psql..." If template0 and template1 start off the same *must* we create it from template0 then? This also confuses the statement above. I think that's enough for y'all to go on. Thanks for the best rdbms out there! - jonas
Re: 13 25.1.1 clarify "The dumps produced by pg_dump are relative to template0"
From
"David G. Johnston"
Date:
On Thursday, September 16, 2021, PG Doc comments form <noreply@postgresql.org> wrote:
The following documentation comment has been logged on the website:
Page: https://www.postgresql.org/docs/13/backup-dump.html
Description:
Unless one knows
that template0 and template1 start off identical the wording above is
confusing because it doesn't make sense why a modified template1 would
necessitate ensuring creation from template0.
It assumes you’ve read chapter 22 before reading chapter 25. At most I’d splice in a hyperlink back to that discussion. A sentence at most probably.
"The database dbname will not be created by this command, so you must create
it yourself from template0 before executing psql..."
If template0 and template1 start off the same *must* we create it from
template0 then? This also confuses the statement above.
Yeah, the main flow and the “important” part are repetitive and could maybe be tweaked a bit. But I don’t see anything wrong. Sure, if one knows template1 is unchanged from template0 then accepting the defaults for create database works. But its somewhat easier to just emphasize that when using create database in preparation for restoring a dump one “must” use template0, as that is definitely safe.
David J.