Re: Pgoutput not capturing the generated columns

Thanks for the patch updates.

Here are my review comments for v21-0001.

I think this patch is mostly OK now except there are still some
comments about the TAP test.

======
Commit Message

0.
Using Create Subscription:
CREATE SUBSCRIPTION sub2_gen_to_gen CONNECTION '$publisher_connstr' PUBLICATION
pub1 WITH (include_generated_columns = true, copy_data = false)"

If you are going to give an example, I think a gen-to-nogen example
would be a better choice. That's because the gen-to-gen (as you have
here) is not going to replicate anything due to the subscriber-side
column being generated.

======
src/test/subscription/t/011_generated.pl

1.
+$node_subscriber2->safe_psql('postgres',
+ "CREATE TABLE tab1 (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a
* 22) STORED, c int)"
+);

The subscriber2 node was intended only for all the tables where we
need include_generated_columns to be true. Mostly that is the
combination tests. (tab_gen_to_nogen, tab_nogen_to_gen, etc) OTOH,
table 'tab1' already existed. I don't think we need to bother
subscribing to tab1 from subscriber2 because every combination is
already covered by the combination tests. Let's leave this one alone.

~~~

2.
Huh? Where is the "tab_nogen_to_gen" combination test that I sent to
you off-list?

~~~

3.
+$node_subscriber->safe_psql('postgres',
+ "CREATE TABLE tab_order (c int GENERATED ALWAYS AS (a * 22) STORED,
a int, b int)"
+);

Maybe you can test 'tab_order' on both subscription nodes but I think
it is overkill. IMO it is enough to test it on subscription2.

~~~

4.
+$node_subscriber->safe_psql('postgres',
+ "CREATE TABLE tab_alter (a int, b int, c int GENERATED ALWAYS AS (a
* 22) STORED)"
+);

Ditto above. Maybe you can test 'tab_order' on both subscription nodes
but I think it is overkill. IMO it is enough to test it on
subscription2.

~~~

5.
Don't forget to add initial data for the missing nogen_to_gen table/test.

~~~

6.
$node_publisher->safe_psql('postgres',
- "CREATE PUBLICATION pub1 FOR ALL TABLES");
+ "CREATE PUBLICATION pub1 FOR TABLE tab1, tab_gen_to_gen,
tab_gen_to_nogen, tab_gen_to_missing, tab_missing_to_gen, tab_order");
+
$node_subscriber->safe_psql('postgres',
"CREATE SUBSCRIPTION sub1 CONNECTION '$publisher_connstr' PUBLICATION pub1"
);

It is not a bad idea to reduce the number of publications as you have
done, but IMO jamming all the tables into 1 publication is too much
because it makes it less understandable instead of simpler.

How about this:
- leave the 'pub1' just for 'tab1'.
- have a 'pub_combo' for publication all the gen_to_nogen,
nogen_to_gen etc combination tests.
- and a 'pub_misc' for any other misc tables like tab_order.

~~~

7.
+#####################
# Wait for initial sync of all subscriptions
+#####################

I think you should write a note here that you have deliberately set
copy_data = false because COPY and include_generated_columns are not
allowed at the same time for patch 0001. And that is why all expected
results on subscriber2 will be empty. Also, say this limitation will
be changed in patch 0002.

~~~

(I didn't yet check 011_generated.pl file results beyond this point...
I'll wait for v22-0001 to review further)

======
Kind Regards,
Peter Smith.
Fujitsu Australia