Re: Re: Segmentation fault in pg_dumpall from master down to 9.1 and other bug introduced by RLS

On Fri, Nov 14, 2014 at 08:39:28PM -0500, Stephen Frost wrote:
> * Noah Misch (noah(at)leadboat(dot)com) wrote:
> > So, if you desire to make this consistent, I recommend using rolreplication's
> > treatment as the gold standard. That is to say, when dumping from an older
> > version, set to false any of these role attributes not existing in that
> > version. Robert's proposal to emit neither NOBYPASSRLS nor BYPASSRLS is a
> > reasonable alternative, though less so for "pg_dumpall --clean". It would be
> > defensible to send NOBYPASSRLS under --clean and omit the option otherwise;
> > consider that my second choice.
>
> I don't see the point in including them for --clean..? --clean states
> that DROP commands would be added, not that existing roles would be
> adjusted in some way.

It does state that, but note this comment in dumpRoles():

/*
* We dump CREATE ROLE followed by ALTER ROLE to ensure that the role
* will acquire the right properties even if it already exists (ie, it
* won't hurt for the CREATE to fail). This is particularly important
* for the role we are connected as, since even with --clean we will
* have failed to drop it. binary_upgrade cannot generate any errors,
* so we assume the current role is already created.
*/

Under --clean, "the right properties" are those the role would have had if the
DROP ROLE had succeeded. Those are necessarily independent of the pre-DROP
version of the role. (Otherwise, you potentially get different outcomes
depending on which superuser restored the --clean dump.)

> As for using 'always false'- I tend to think Robert actually has it
> better by using the default for users. Consider rolinherit- that
> defaults to 'true' and while it would technically be more 'safe' to set
> it to false, it wouldn't have matched what we provided under the user /
> group system prior to roles. Doing this would also reduce clutter in
> pg_dumpall output.

My arguments and conclusion apply only to the permission-like attributes that
are subsets of SUPERUSER. rolinherit is indeed not in that category.