Re: [Patch] Omit virtual generated columns from test_decoding output

Hi,

On Thu, May 7, 2026 at 9:31 PM Fujii Masao <masao(dot)fujii(at)gmail(dot)com> wrote:
>
> > Fair concern, I moved the tests to ddl.sql. Please find the attached v2 patch.
>
> Seems you forgot to attached the patch.

I agree we must fix this for test_decoding. Here's my take.

When a column holding a genuine NULL value gets decoded, it shows up
as null in the output. But a virtual generated column also shows up as
null, so the two are hard to tell apart in the test_decoding output
today.

table public.t: INSERT: a[integer]:1 b[integer]:null c[integer]:null
d[integer]:100

Here b is a genuine NULL and c is a virtual generated column whose
value is 10 (for example), but both show up as null.

That gives me two reasons to +1 this patch:

1/ It's hard to distinguish in the test_decoding output whether a
column is a genuine NULL or a virtual generated column. For example:
2/ The pgoutput already skips virtual generated columns in
logicalrep_should_publish_column().

I quickly reviewed the v3 patch and it looks good to me. However,
pgindent was not happy, so I ran it, tweaked the comments and commit
message a bit, ran the tests, and attached a v4 patch. Please have a
look.

I prefer to back-patch this through PG18, where virtual generated
columns were introduced (commit 83ea6c54025).

--
Bharath Rupireddy
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