On Tue, Oct 12, 2021 at 08:49:28AM -0400, Stephen Frost wrote: > * Bruce Momjian (br...@momjian.us) wrote: > > I thought he was saying that when you extend a file, you might have to > > extend it with all zeros, rather than being able to extend it with > > an actual encrypted page of zeros. For example, I think when a page is > > corrupt in storage, it reads back as a fully zero page, and we would > > need to handle that. Are you saying we already have logic to handle > > that so we don't need to change anything? > > When we extend a file, it gets extended with all zeros. PG already > handles that case, PG w/ TDE would need to also recognize that case > (which is what Ants was saying their patch does) and handle it. In > other words, we just need to realize when a page is all zeros and not > try to decrypt it when we're reading it. Ants' patch does that and my > recollection is that it wasn't very complicated to do, and that seems > much simpler than trying to figure out a way to ensure we do encrypt a > zero'd page as part of extending a file.
Well, how do you detect an all-zero page vs a page that encrypted to all zeros? I am thinking a zero LSN (which is not encrypted) would be the only sure way, but we then have to make sure unlogged relations always get a fake LSN. -- Bruce Momjian <br...@momjian.us> https://momjian.us EDB https://enterprisedb.com If only the physical world exists, free will is an illusion.
