Re: BUG #16978: Nested CTEs give ERROR in v13

On Fri, Apr 23, 2021 at 10:08:06AM -0400, Tom Lane wrote:
> PG Bug reporting form <noreply(at)postgresql(dot)org> writes:
> > This narrowed down SQL (from what SQLSmith generated) seems to error out
> > only with N levels of CTE nesting - no tables / views / 1-row output.
> > The SQL works fine with v12.4 but raises an ERROR in v13 which seems like a
> > regression. Is this owing a recent change in v13 - that could affect this?
>
> FWIW, I don't see any error from this, either in HEAD or the
> back branches.
>
> $ cat recursive.sql
> WITH RECURSIVE w6(c6) AS
> (WITH w6(c6) AS
> (WITH w8(c8) AS
> (WITH w9(c9) AS
> (WITH w10(c10) AS
> (WITH w11(c11) AS
> (WITH w_err(c12) AS
> (SELECT 1)
> SELECT * FROM w_err)
> SELECT * FROM w11)
> SELECT * FROM w10)
> SELECT * FROM w9)
> SELECT * FROM w8)
> SELECT * FROM w6)
> SELECT * FROM w6;
> $ psql -f recursive.sql
> c6
> ----
> 1
> (1 row)

Uh, I don't see the failure in 13 head or master, but I do see it from a
13.2 tree checkout. I will try to find the post-13.2 commit cause.

--
Bruce Momjian <bruce(at)momjian(dot)us> https://momjian.us
EDB https://enterprisedb.com

If only the physical world exists, free will is an illusion.