Re: Optimize mergejoinscansel() by avoiding redundant computations

Hi,
Sorry, I forgot to include the initialization SQL.

drop table if exists pg_class_1;
drop table if exists pg_class_2;

select max(oid) from pg_catalog.pg_class;

create table pg_class_1 as select * from pg_catalog.pg_class where oid < 13673 WITH DATA;
create table pg_class_2 as select * from pg_class_1 WITH DATA;

analyze pg_class_1, pg_class_2;

select count(*) from pg_class_1;
select count(*) from pg_class_2;

explain (summary) select a.reltype from pg_class_1 a, pg_class_1 b where a.reltype = b.reltype;
explain (summary) select a.reltype from pg_class_1 a, pg_class_2 b where a.reltype = b.reltype;

regards,
--
ZizhuanLiu (X-MAN) 
44973863(at)qq(dot)com