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From: Tom Lane <tgl@sss.pgh.pa.us>
To: "David G. Johnston" <david.g.johnston@gmail.com>
cc: Ron <ronljohnsonjr@gmail.com>, pgsql-admin@lists.postgresql.org
Subject: Re: vacuumdb maintenance-db??
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Comments: In-reply-to "David G. Johnston" <david.g.johnston@gmail.com>
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"David G. Johnston" <david.g.johnston@gmail.com> writes:
> On Wed, Nov 9, 2022 at 1:54 PM Ron <ronljohnsonjr@gmail.com> wrote:
>> But this raises a different question: when does the postgres database not
>> exist?

> You are giving it too much specialness.  Both ALTER DATABASE ... RENAME and
> DROP DATABASE can be used on it.

The template databases aren't all that special either.  There is a defense
against dropping them accidentally:

regression=# drop database template1;
ERROR:  cannot drop a template database

but you can override that if you really mean it:

regression=# alter database template1 with is_template false;
ALTER DATABASE
regression=# drop database template1;
DROP DATABASE

This might seem pretty scary, but it's intentional, per the comments
in IsPinnedObject:

     * Databases are never pinned.  It might seem that it'd be prudent to pin
     * at least template0; but we do this intentionally so that template0 and
     * template1 can be rebuilt from each other, thus letting them serve as
     * mutual backups (as long as you've not modified template1, anyway).

			regards, tom lane