Horton

Re: Key management with tests

Masahiko Sawada <sawada.mshk@gmail.com>

View thread
From: Masahiko Sawada <sawada.mshk@gmail.com>
To: Stephen Frost <sfrost@snowman.net>
Cc: Bruce Momjian <bruce@momjian.us>, Thomas Munro <thomas.munro@gmail.com>, PostgreSQL-development <pgsql-hackers@postgresql.org>, Masahiko Sawada <masahiko.sawada@2ndquadrant.com>
Date: 2021-01-12T00:32:54Z
Lists: pgsql-hackers

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →

  1. Rethink method for assigning OIDs to the template0 and postgres DBs.

  2. pg_upgrade: Preserve database OIDs.

  3. pg_upgrade: Preserve relfilenodes and tablespace OIDs.

  4. Fix for new Boolean node

  5. Improve error handling of HMAC computations

  6. Add macro RelationIsPermanent() to report relation permanence

  7. Enhance nbtree index tuple deletion.

On Tue, Jan 12, 2021 at 3:23 AM Stephen Frost <sfrost@snowman.net> wrote:
>
> Greetings,
>
> * Bruce Momjian (bruce@momjian.us) wrote:
> > On Mon, Jan 11, 2021 at 12:54:49PM -0500, Stephen Frost wrote:
> > > Although, another approach and one that I've discussed a bit with Bruce,
> > > is to have more keys- such as a key for temporary files, and perhaps
> > > even a key for logged relations and a different for unlogged..  Or
> >
> > Yes, we have to make sure the nonce (computed as LSN/pageno) is never
> > reused, so if we have several LSN usage "spaces", they need different
> > data keys.
>
> Right, or ensure that the actual IV used is distinct (such as by using
> another bit in the IV to distinguish logged-vs-unlogged), but it seems
> saner to just use a different key, ultimately.

Agreed.

I think we also need to consider how to make sure nonce is unique when
making a page dirty by updating hint bits. Hint bit update changes the
page contents but doesn't change the page lsn if we already write a
full page write. In the PoC patch, I logged a dummy WAL record
(XLOG_NOOP) just to move the page lsn forward, but since this is
required even when changing the page is not the first time since the
last checkpoint we might end up logging too many dummy WAL records.

Regards,

-- 
Masahiko Sawada
EnterpriseDB:  https://www.enterprisedb.com/