On Fri, Apr 5, 2024 at 09:41:05AM +0200, Daniel Gustafsson wrote:
> > On 5 Apr 2024, at 06:47, Rama Krishnan <raghuldrag@gmail.com> wrote:
>
> > Could you please explain me how does pg_upgrade works one of my friends it works based on pg_restore I am bit
confused
>
> The documentation does a fairly good job explaining how it works, and there are
> multiple blogposts and presentations on the subject to be found.
>
> https://www.postgresql.org/docs/devel/pgupgrade.html
>
> To summarize in a few words, pg_upgrade does a dump/restore of the schema from
> the old cluster into the new, but copies the table data. Your friend is thus
> isn't wrong, it does use pg_restore but only for the schema, not the data.
This presentation shows how it works internally:
https://momjian.us/main/writings/pgsql/pg_upgrade.pdf
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Bruce Momjian <bruce@momjian.us> https://momjian.us
EDB https://enterprisedb.com
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