Thread

Re: Changing the state of data checksums in a running cluster

SATYANARAYANA NARLAPURAM <satyanarlapuram@gmail.com> — 2026-05-01T16:57:20Z

Hi Daniel,

On Thu, Apr 30, 2026 at 8:20 AM Daniel Gustafsson <daniel@yesql.se> wrote:

> > On 29 Apr 2026, at 15:42, Ayush Tiwari <ayushtiwari.slg01@gmail.com>
> wrote:
>
> > The patchset looks good.
>
> Thanks for review, I've applied the patchset after some editorializing.
>

While further testing this feature, I realized that
ProcessSingleRelationFork()
unconditionally called log_newpage_buffer() for every page of every
relation
during pg_enable_data_checksums(). This included unlogged relations,
which by definition never generate WAL for data changes and are reset to
their
init fork on any recovery.

Guard the log_newpage_buffer() call with RelationNeedsWAL() so that
unlogged relations still get their pages dirtied (ensuring the checksum
is flushed to disk at the next checkpoint) but do not emit WAL.

Attached a patch to address this and added a test for the same. My current
test checks if standby has main fork, I could just checked WAL to verify
this
using pg_waldump. Any other test ideas are welcome.

Thanks,
Satya