Re: BUG #18244: Corruption in indexes involving whole-row expressions

On Wed, Dec 13, 2023 at 11:53 AM Laurenz Albe <laurenz.albe@cybertec.at> wrote:
> On Tue, 2023-12-12 at 19:28 +0000, PG Bug reporting form wrote:
> > nik=# create index on t1 (hash_record(t1));
> >
> > Such an index can easily be corrupted, e.g.:
> >
> > nik=#  alter table t1 add column yo int default -1;
> >
> > Proposal: prohibit the use of whole-row expression – as it is already done
> > for generated columns and produce a similar error ("cannot use whole-row
> > variable in column generation expression")
>
> I reported that bug before:
> https://www.postgresql.org/message-id/flat/e48a5d9a2d3d72985d61ee254314f5f5f5444a55.camel%40cybertec.at

FTR I also posted a repro for another variation of that problem.  I
think it's slightly more general that, it not just whole-row
expressions (eg index on <table_name>), it's row types generally:

https://www.postgresql.org/message-id/CA%2BhUKGKb4SB%2BqQ-vAVomxAvJY6um%2B5URyq2D0vv10g7mbYZ1Ww%40mail.gmail.com