Richard Guo <guofenglinux@gmail.com> writes: > On Wed, Aug 30, 2023 at 7:42 PM Richard Guo <guofenglinux@gmail.com> wrote: >> When we expand Var 'c1' from func(c1), we figure out that it comes from >> subquery 's'. When we recurse into subquery 's', we just build an >> additional level of ParseState atop the current ParseState, which seems >> not correct. Shouldn't we climb up by the nesting depth first before we >> build the additional level of ParseState? Something like >> ...
> Here is the patch.
Yeah, I think your diagnosis is correct. The existing regression tests reach this code path, but not with netlevelsup different from zero. I noted from the code coverage report that the same is true of the nearby RTE_CTE code path: that does have a loop to crawl up the pstate stack, but it isn't getting iterated. The attached improved patch extends the test case so it also covers that.
+1 to the v2 patch.
BTW, do you think get_name_for_var_field() has similar problem for RTE_SUBQUERY case? The RTE_CTE code path in that function crawls up the namespace stack before recursing into the CTE while the RTE_SUBQUERY code patch does not, which looks like an oversight. I tried to find a test case to show it's indeed a problem but with no luck.
