gzh <gzhcoder(at)126(dot)com> writes:
> I upgraded the version of PostgreSQL from 12.13 to 12.16.
> If multiple subqueries or a large number of UNION ALL were used,
> the previously unseen error message "ERROR: stack depth limit exceeded" will appear after upgrading the version.
Please provide a self-contained example. The people who might be
able to fix this are too busy to guess about what you are seeing.
regards, tom lane