Re: Use read streams in pg_visibility

Hi,

On Tue, 10 Sept 2024 at 00:32, Noah Misch <noah(at)leadboat(dot)com> wrote:
>
> Copying the vm file is a good technique. In my test runs, this does catch the
> "never detect" bug, but it doesn't catch the blkno bug. Can you make it catch
> both? It's possible my hand-patching to recreate the blkno bug is what went
> wrong, so I'm attaching what I used. It consists of
> v1-0002-Use-read-stream-in-pg_visibility-in-collect_corru.patch plus these
> fixes for the "never detect" bug from your v6-0002:

Your patch is correct. I wrongly assumed it would catch blockno bug,
the attached version catches it. I made blockno = 0 invisible and not
frozen before copying the vm file. So, in the blockno buggy version;
callback will skip that block but the main loop in the
collect_corrupt_items() will not skip it. I tested it with your patch
and there is exactly 1 blockno difference between expected and result
output.

--
Regards,
Nazir Bilal Yavuz
Microsoft