Re: pg_dump bug fixing

> I've just found a bit of undesirable functionality which I would call a bug in 
> pg_dump.   I'm not sure everyone would, but we'll see.
> 
> Problem:  the script which dumps globals such as users (pg_dumpall -g) 
> involves deleting *all* users from the pg_shadow table via a direct update to 
> that table.   What this means in effect is that, should you attempt to use 
> "pg_dumpall -g" to *move* a set of users from one active server to another 
> (such as for transferring a database) the resulting pg_dump file will delete 
> all of the users which previously existed on that server.
> 
> This is a non-trivial accident to have happen on a shared machine; once users 
> are dumped, all of their ownerships and permissions go with them.   If you 
> have a complex permissions system, better hope you backed up first!
> 
> I find this behavior highly undesirable, and consider it a bug.    The globals 
> dump should just add users, and not delete any.

Yeah, it's nasty.  One of the fixes that's already in from me is to make 
the DELETE FROM pg_shadow and DELETE FROM pg_group only appear when -c 
mode is set.

Maybe even when -c mode is set we should use DROP USER commands?

Do others agree?

Chris