set autocommit=1;
create database db_1;
create table db_1.t1(
id int primary key auto_increment,
col1 varchar(100),
col2 int
)engine= innodb;
select count(*) from db_1.t1 as of gcn 2048 where id > 0;
count(*)
10
select count(*) from db_1.t1 as of gcn 2048 where id > 0;
count(*)
10
show global status like '%tcn_cache%';
Variable_name	Value
Lizard_block_tcn_cache_hit	0
Lizard_block_tcn_cache_miss	0
Lizard_block_tcn_cache_evict	0
Lizard_session_tcn_cache_hit	10
Lizard_session_tcn_cache_miss	10
Lizard_session_tcn_cache_evict	10
Lizard_global_tcn_cache_hit	0
Lizard_global_tcn_cache_miss	0
Lizard_global_tcn_cache_evict	0
set global innodb_tcn_cache_level = block;
select count(*) from db_1.t1 as of gcn 2048 where id > 0;
count(*)
10
select count(*) from db_1.t1 as of gcn 2048 where id > 0;
count(*)
10
show global status like '%tcn_cache%';
Variable_name	Value
Lizard_block_tcn_cache_hit	10
Lizard_block_tcn_cache_miss	10
Lizard_block_tcn_cache_evict	10
Lizard_session_tcn_cache_hit	10
Lizard_session_tcn_cache_miss	10
Lizard_session_tcn_cache_evict	10
Lizard_global_tcn_cache_hit	0
Lizard_global_tcn_cache_miss	0
Lizard_global_tcn_cache_evict	0
set global innodb_tcn_cache_level=session;
drop table db_1.t1;
drop database db_1;