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

[Sudarshan m]

when i do show index some_table its shows below . That means index exist , please correct me if i am wrong.

mysql> SHOW INDEX FROM some_table;
+---------------+------------+----------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+---------------+---------+------------+
| Table | Non_unique | Key_name | Seq_in_index | Column_name | Collation | Cardinality | Sub_part | Packed | Null | Index_type | Comment | Index_comment | Visible | Expression |
+---------------+------------+----------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+---------------+---------+------------+
| some_table | 0 | PRIMARY | 1 | variableid | A | 1708576 | NULL | NULL | | BTREE | | | YES | NULL |
| some_table | 0 | PRIMARY | 2 | name | A | 117891808 | NULL | NULL | | BTREE | | | YES | NULL |
+---------------+------------+----------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+---------------+---------+------------+
2 rows in set (0.00 sec)



Query is: Select * from some_table; we need all the data after some interval say 12hours everyday.