DROP TABLE if exists t1;
select @@global.innodb_stats_persistent;
@@global.innodb_stats_persistent
0
set global innodb_defragment_stats_accuracy = 20;
# Create table.
CREATE TABLE t1 (a INT NOT NULL PRIMARY KEY AUTO_INCREMENT, b VARCHAR(256), KEY SECOND(a, b)) ENGINE=INNODB;
# Populate data
INSERT INTO t1 VALUES(1, REPEAT('A', 256));
INSERT INTO t1 (b) SELECT b from t1;
INSERT INTO t1 (b) SELECT b from t1;
INSERT INTO t1 (b) SELECT b from t1;
INSERT INTO t1 (b) SELECT b from t1;
INSERT INTO t1 (b) SELECT b from t1;
INSERT INTO t1 (b) SELECT b from t1;
INSERT INTO t1 (b) SELECT b from t1;
INSERT INTO t1 (b) SELECT b from t1;
INSERT INTO t1 (b) SELECT b from t1;
INSERT INTO t1 (b) SELECT b from t1;
# Not enough page splits to trigger persistent stats write yet.
select count(stat_value) = 0 from mysql.innodb_index_stats where table_name like '%t1%' and  stat_name in ('n_page_split');
count(stat_value) = 0
1
select count(stat_value) = 0 from mysql.innodb_index_stats where table_name like '%t1%' and  stat_name in ('n_pages_freed');
count(stat_value) = 0
1
select count(stat_value) = 0 from mysql.innodb_index_stats where table_name like '%t1%' and  stat_name in ('n_leaf_pages_defrag');
count(stat_value) = 0
1
INSERT INTO t1 (b) SELECT b from t1;
# Persistent stats recorded.
select count(stat_value) > 0 from mysql.innodb_index_stats where table_name like '%t1%' and  stat_name in ('n_page_split');
count(stat_value) > 0
1
select count(stat_value) = 0 from mysql.innodb_index_stats where table_name like '%t1%' and  stat_name in ('n_pages_freed');
count(stat_value) = 0
1
select count(stat_value) > 0 from mysql.innodb_index_stats where table_name like '%t1%' and  stat_name in ('n_leaf_pages_defrag');
count(stat_value) > 0
1
# Delete some rows.
delete from t1 where a between 100 * 20 and 100 * 20 + 30;
delete from t1 where a between 100 * 19 and 100 * 19 + 30;
delete from t1 where a between 100 * 18 and 100 * 18 + 30;
delete from t1 where a between 100 * 17 and 100 * 17 + 30;
delete from t1 where a between 100 * 16 and 100 * 16 + 30;
delete from t1 where a between 100 * 15 and 100 * 15 + 30;
delete from t1 where a between 100 * 14 and 100 * 14 + 30;
delete from t1 where a between 100 * 13 and 100 * 13 + 30;
delete from t1 where a between 100 * 12 and 100 * 12 + 30;
delete from t1 where a between 100 * 11 and 100 * 11 + 30;
delete from t1 where a between 100 * 10 and 100 * 10 + 30;
delete from t1 where a between 100 * 9 and 100 * 9 + 30;
delete from t1 where a between 100 * 8 and 100 * 8 + 30;
delete from t1 where a between 100 * 7 and 100 * 7 + 30;
delete from t1 where a between 100 * 6 and 100 * 6 + 30;
delete from t1 where a between 100 * 5 and 100 * 5 + 30;
delete from t1 where a between 100 * 4 and 100 * 4 + 30;
delete from t1 where a between 100 * 3 and 100 * 3 + 30;
delete from t1 where a between 100 * 2 and 100 * 2 + 30;
delete from t1 where a between 100 * 1 and 100 * 1 + 30;
# Server Restarted
# Confirm persistent stats still there after restart.
select count(stat_value) > 0 from mysql.innodb_index_stats where table_name like '%t1%' and  stat_name in ('n_page_split');
count(stat_value) > 0
1
select count(stat_value) = 0 from mysql.innodb_index_stats where table_name like '%t1%' and  stat_name in ('n_pages_freed');
count(stat_value) = 0
1
select count(stat_value) > 0 from mysql.innodb_index_stats where table_name like '%t1%' and  stat_name in ('n_leaf_pages_defrag');
count(stat_value) > 0
1
optimize table t1;
Table	Op	Msg_type	Msg_text
test.t1	optimize	status	OK
select sleep(2);
sleep(2)
0
select count(stat_value) > 0 from mysql.innodb_index_stats where table_name like '%t1%' and  stat_name in ('n_page_split');
count(stat_value) > 0
1
select count(stat_value) > 0 from mysql.innodb_index_stats where table_name like '%t1%' and  stat_name in ('n_pages_freed');
count(stat_value) > 0
1
select count(stat_value) > 0 from mysql.innodb_index_stats where table_name like '%t1%' and  stat_name in ('n_leaf_pages_defrag');
count(stat_value) > 0
1
set global innodb_defragment_stats_accuracy = 40;
INSERT INTO t1 (b) SELECT b from t1;
select count(stat_value) > 0 from mysql.innodb_index_stats where table_name like '%t1%' and  stat_name in ('n_page_split');
count(stat_value) > 0
1
select count(stat_value) > 0 from mysql.innodb_index_stats where table_name like '%t1%' and  stat_name in ('n_pages_freed');
count(stat_value) > 0
1
select count(stat_value) > 0 from mysql.innodb_index_stats where table_name like '%t1%' and  stat_name in ('n_leaf_pages_defrag');
count(stat_value) > 0
1
INSERT INTO t1 (b) SELECT b from t1;
select count(stat_value) > 0 from mysql.innodb_index_stats where table_name like '%t1%' and  stat_name in ('n_page_split');
count(stat_value) > 0
1
select count(stat_value) > 0 from mysql.innodb_index_stats where table_name like '%t1%' and  stat_name in ('n_pages_freed');
count(stat_value) > 0
1
select count(stat_value) > 0 from mysql.innodb_index_stats where table_name like '%t1%' and  stat_name in ('n_leaf_pages_defrag');
count(stat_value) > 0
1
# Table rename should cause stats rename.
rename table t1 to t2;
select sleep(1);
sleep(1)
0
select count(stat_value) = 0 from mysql.innodb_index_stats where table_name like '%t1%' and  stat_name in ('n_page_split');
count(stat_value) = 0
1
select count(stat_value) = 0 from mysql.innodb_index_stats where table_name like '%t1%' and  stat_name in ('n_pages_freed');
count(stat_value) = 0
1
select count(stat_value) = 0 from mysql.innodb_index_stats where table_name like '%t1%' and  stat_name in ('n_leaf_pages_defrag');
count(stat_value) = 0
1
select count(stat_value) > 0 from mysql.innodb_index_stats where table_name like '%t2%' and  stat_name in ('n_page_split');
count(stat_value) > 0
1
select count(stat_value) > 0 from mysql.innodb_index_stats where table_name like '%t2%' and  stat_name in ('n_pages_freed');
count(stat_value) > 0
1
select count(stat_value) > 0 from mysql.innodb_index_stats where table_name like '%t2%' and  stat_name in ('n_leaf_pages_defrag');
count(stat_value) > 0
1
# Drop index should cause stats drop.
drop index SECOND on t2;
select sleep(3);
sleep(3)
0
select count(stat_value) > 0 from mysql.innodb_index_stats where table_name like '%t2%' and index_name = 'SECOND' and  stat_name in ('n_page_split');
count(stat_value) > 0
1
select count(stat_value) > 0 from mysql.innodb_index_stats where table_name like '%t2%' and index_name = 'SECOND' and  stat_name in ('n_pages_freed');
count(stat_value) > 0
1
select count(stat_value) > 0 from mysql.innodb_index_stats where table_name like '%t2%' and index_name = 'SECOND' and stat_name in ('n_leaf_pages_defrag');
count(stat_value) > 0
1
Server Restarted
select count(stat_value) = 0 from mysql.innodb_index_stats where table_name like '%t1%' and  stat_name in ('n_page_split');
count(stat_value) = 0
1
select count(stat_value) = 0 from mysql.innodb_index_stats where table_name like '%t1%' and  stat_name in ('n_pages_freed');
count(stat_value) = 0
1
select count(stat_value) = 0 from mysql.innodb_index_stats where table_name like '%t1%' and  stat_name in ('n_leaf_pages_defrag');
count(stat_value) = 0
1
select count(stat_value) > 0 from mysql.innodb_index_stats where table_name like '%t2%' and  stat_name in ('n_page_split');
count(stat_value) > 0
1
select count(stat_value) > 0 from mysql.innodb_index_stats where table_name like '%t2%' and  stat_name in ('n_pages_freed');
count(stat_value) > 0
1
select count(stat_value) > 0 from mysql.innodb_index_stats where table_name like '%t2%' and  stat_name in ('n_leaf_pages_defrag');
count(stat_value) > 0
1
# Clean up
DROP TABLE t2;
select count(stat_value) = 0 from mysql.innodb_index_stats where table_name like '%t2%' and  stat_name in ('n_page_split');
count(stat_value) = 0
1
select count(stat_value) = 0 from mysql.innodb_index_stats where table_name like '%t2%' and  stat_name in ('n_pages_freed');
count(stat_value) = 0
1
select count(stat_value) = 0 from mysql.innodb_index_stats where table_name like '%t2%' and  stat_name in ('n_leaf_pages_defrag');
count(stat_value) = 0
1