Thread: 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@gmail.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;