Re: EXPLAIN(VERBOSE) to CTE with SEARCH BREADTH FIRST fails

torikoshia <torikoshia(at)oss(dot)nttdata(dot)com> writes:
> While working on [1], we found that EXPLAIN(VERBOSE) to CTE with SEARCH
> BREADTH FIRST ends up ERROR.

Yeah. It's failing here:

* We're deparsing a Plan tree so we don't have a CTE
* list. But the only place we'd see a Var directly
* referencing a CTE RTE is in a CteScan plan node, and we
* can look into the subplan's tlist instead.

if (!dpns->inner_plan)
elog(ERROR, "failed to find plan for CTE %s",
rte->eref->aliasname);

The problematic Var is *not* in a CteScan plan node; it's in a
WorkTableScan node. It's not clear to me whether this is a bug
in the planner's handling of SEARCH BREADTH FIRST, or if the plan
is as-intended and ruleutils.c is failing to cope.

Either way, this deserves an open item...

regards, tom lane