Reader Gang's old catcache not cleard

[kainwen]

Bug Report

Greenplum version or build

Tested on master branch with top commit ( 58cb8cf4320bded3b7bca45489575f3412ec5eff ).

But seems for me this impact all versions of gpdb. I try but not manage to build other bad case for gp6.

Step to reproduce the behavior

Firstly, we need to set ORCA on.

create table dml_union_s (a int not null, b numeric default 10.00) distributed by (a) partition by range(b);
create table dml_union_s_1_prt_2 partition of dml_union_s for values from (1) to (1001);
create table dml_union_s_1_prt_def partition of dml_union_s default;

insert into dml_union_s select generate_series(1,10), generate_series(1,10);

begin;
drop table dml_union_s_1_prt_def;
-- it is this SQL need run under orca to reproduce the issue
select count(distinct(b)) from dml_union_s;
rollback;

-- this SQL fallback to planner now
update dml_union_s set a = (select null union select null)::numeric;

Get the error:

psql:a.sql:14: ERROR:  expected partdefid 16396, but got 0 (partdesc.c:193)  (seg2 slice2 127.0.1.1:7004 pid=41797) (partdesc.c:193)

[kainwen]

Discussion https://groups.google.com/a/greenplum.org/g/gpdb-dev/c/u3-D7isdvmM

[kainwen]

https://github.com/greenplum-db/gpdb/pull/14048