On 2019-Jul-05, Stephen Frost wrote:
> I had been specifically thinking of tablespaces because we might be able
> to do something exactly along these lines- keep which tablespace the
> data is in directly in the WAL (and not encrypted), but then have the
> data itself be encrypted, and with the key for that tablespace.
Hmm, I was imagining that the user-level data is encrypted, while the
metadata such as the containing relfilenode is not encrypted and thus
can be read by system processes such as checkpointer or WAL-apply
without needing to decrypt anything. Maybe I'm just lacking imagination
for an attack that uses that unencrypted metadata, though.
> Splitting the WAL by tablespace would be even nicer, of course... :)
Hmm, I think you would have to synchronize the apply anyway (i.e. not
replay in one tablespace ahead of a record in another tablespace with an
earlier LSN.) What are you thinking are the gains of doing that, anyway?
--
Álvaro Herrera https://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
