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

Hi,

I think there's a minor issue in how pg_checksums validates state before
checking the data.

The current patch simply does:

  if (ControlFile->data_checksum_version == 0 &&
      mode == PG_MODE_CHECK)
      pg_fatal("data checksums are not enabled in cluster");

and that worked when the version was either 0 or 1. But now it can be
also 2 or 3, for inprogress-on / inprogress-off, and if the cluster gets
shut down at the right moment, that can end in the control file.

It doesn't make sense to verify checksums in such cluster, pg_checksums
should handle that as "off", i.e. error out.


regards

-- 
Tomas Vondra