BUG #18414: When the key values are the same, the memory limit is exceeded when making a hash join

The following bug has been logged on the website:

Bug reference: 18414
Logged by: linfeng chen
Email address: 723609220apple(at)gmail(dot)com
PostgreSQL version: 16.2
Operating system: openeuler
Description:

/*
* Did this batch receive ALL of the tuples from its
* parent batch? That would indicate that further
* repartitioning isn't going to help (the hash values
* are probably all the same).
*/
create table t1(a int);
create table t2(a int);
insert into t1 values(1);
insert into t1 select * from t1;
insert into t1 select * from t1;
insert into t1 select * from t1;
insert into t1 select * from t1;
insert into t1 select * from t1;
insert into t1 select * from t1;
insert into t1 select * from t1;
insert into t1 select * from t1;
insert into t1 select * from t1;
insert into t1 select * from t1;
insert into t1 select * from t1;
insert into t1 select * from t1;
insert into t1 select * from t1;
insert into t1 select * from t1;
insert into t1 select * from t1;
insert into t1 select * from t1;
insert into t2 select * from t1;
select count(*) from t1 join t2 on t1.a=t2.a;