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

Hi,

I spent a bit more time doing some testing on the last version of the
patch from [1]. And I ran into this assert in PostmasterStateMachine()
when stopping the cluster:

/* All types should be included in targetMask or remainMask */
Assert((remainMask.mask | targetMask.mask) == BTYPE_MASK_ALL.mask);

At first I was puzzled as this happens on every shutdown, but that's
because these checks were introduced by a78af0427015 a week ago. So it's
more a matter of rebasing.

However, I also noticed the progress monitoring does not really work. I
get stuff like this:

+ psql -x test -c 'select * from pg_stat_progress_data_checksums'
-[ RECORD 1 ]---------------------+---------
pid | 56811
datid | 0
datname |
phase | enabling
databases_total | 4
relations_total |
databases_processed | 0
relations_processed | 0
databases_current | 16384
relation_current | 0
relation_current_blocks | 0
relation_current_blocks_processed | 0

But I've never seen any of the "processed" fields to be non-zero (and
relations is even NULL), and the same thing applies to relation_. Also
what is the datid/datname about? It's empty, not mentioned in sgml docs,
and we already have databases_current ...

The message [2] from 10/08 says:

> I did remove parts of the progress reporting for now since it can't be
> used from the dynamic backgroundworker it seems. I need to regroup
> and figure out a better way there, but I wanted to address your above
> find sooner rather than wait for that.

And I guess that would explain why some of the fields are not updated.
But then the later patch versions seem to imply there are no outstanding
issues / missing stuff.

regards

[1]
https://www.postgresql.org/message-id/CA226DE1-DC9A-4675-A83C-32270C473F0B%40yesql.se

[2]
https://www.postgresql.org/message-id/DD25705F-E75F-4DCA-B49A-5578F4F55D94%40yesql.se

--
Tomas Vondra