Re: [HACKERS] Refactor handling of database attributes between pg_dump and pg_dumpall

Hmm ... so there's a small problem with this idea of dropping and
recreating template1:

pg_restore: connecting to database for restore
pg_restore: dropping DATABASE template1
pg_restore: [archiver (db)] Error while PROCESSING TOC:
pg_restore: [archiver (db)] Error from TOC entry 3024; 1262 1 DATABASE template1
postgres
pg_restore: [archiver (db)] could not execute query: ERROR: cannot drop a templ
ate database
Command was: DROP DATABASE "template1";

Now in principle we could hack around that by issuing "ALTER DATABASE
... IS_TEMPLATE false" first, but it turns out to be harder than you
might think to wedge that into the pg_dump infrastructure. (The
natural way to do it, trying to add this into the dropCmd for the
database TOC entry, fails because (a) DROP DATABASE then ends up as
one part of an implicit transaction block, and (b) it confuses the heck
out of pg_restore's --if-exists kluge.)

You can actually exhibit this in current releases if you try "pg_dump
--clean --create" on a user-created template database, so it's not
solely the fault of this patch.

What do people think of just removing this DROP DATABASE restriction?
Arguably, superusers should know better than to drop template1 anyway.
Maybe we should replace it with a hard-wired check against dropping
template0 (matched by name) just to stave off the worst-case scenario.

regards, tom lane