Re: why MySql 8.0.17 Select query performance is slower than Mysql 5.7.26?

[Sudarshan m]

+----+-------------+---------------+------------+------+---------------+------
Explain
+---------+------+-----------+----------+-------+
| id | select_type | table | partitions | type | possible_keys | key | key_len | ref | rows | filtered | Extra |
+----+-------------+---------------+------------+------+---------------+------+---------+------+-----------+----------+-------+
| 1 | SIMPLE | Some_Table | NULL | ALL | NULL | NULL | NULL | NULL | 118544457 | 100.00 | NULL |
+----+-------------+---------------+------------+------+---------------+------+---------+------+-----------+----------+-------+



mysql> SHOW CREATE TABLE Some_Table;
+---------------+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Table | Create Table |
+---------------+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Some_Table | CREATE TABLE `Some_Table` (
`variableid` bigint(20) NOT NULL,
`name` char(8) CHARACTER SET ascii NOT NULL,
`value` varchar(1024) CHARACTER SET utf8 COLLATE utf8_bin NOT NULL,
PRIMARY KEY (`variableid`,`name`)
) ENGINE=MyISAM DEFAULT CHARSET=utf8 |