Horton

Re: [Proposal] Table-level Transparent Data Encryption (TDE) and Key Management Service (KMS)

Antonin Houska <ah@cybertec.at>

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From: Antonin Houska <ah@cybertec.at>
To: Robert Haas <robertmhaas@gmail.com>
Cc: Bruce Momjian <bruce@momjian.us>, Sehrope Sarkuni <sehrope@jackdb.com>, Masahiko Sawada <sawada.mshk@gmail.com>, Joe Conway <mail@joeconway.com>, Stephen Frost <sfrost@snowman.net>, Tomas Vondra <tomas.vondra@2ndquadrant.com>, Haribabu Kommi <kommi.haribabu@gmail.com>, "Moon, Insung" <Moon_Insung_i3@lab.ntt.co.jp>, Ibrar Ahmed <ibrar.ahmad@gmail.com>, PostgreSQL-development <pgsql-hackers@postgresql.org>
Date: 2019-11-02T12:24:37Z
Lists: pgsql-hackers

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

  1. Revamp the WAL record format.

Robert Haas <robertmhaas@gmail.com> wrote:

> On Mon, Aug 5, 2019 at 8:44 PM Bruce Momjian <bruce@momjian.us> wrote:
> > Right.  The 8k page LSN changes each time the page is modified, and the
> > is part of the page nonce.
> 
> What about hint bit changes?
> 
> I think even with wal_log_hints=on, it's not the case that *every*
> change to hint bits results in an LSN change.

Change to hint bits does not result in LSN change in the case I described here

https://www.postgresql.org/message-id/28452.1572443058%40antos

but I consider this a bug (BTW, I discovered this problem when thinking about
the use of LSN as encryption IV). Do you mean any other case? If LSN does not
get changed, then the related full-page image WAL record is not guaranteed to
be on disk during crash recovery. Thus if page checksum is invalid due to
torn-page write, there's now WAL record to fix the page.

-- 
Antonin Houska
Web: https://www.cybertec-postgresql.com