0801~ Interview questions

What is the difference between the storage engine InnoDB and MyISAM?

InnoDB supports transactions, while MyISAM does not;

InnoDB can set foreign keys, while MyISAM does not support foreign keys;

InnoDB query select count(1) requires table scan, and MyISAM has variables to count the number;

InnoDB is a clustered index, while MySAM is a non-clustered index;

What is the difference between truncate, delete, and drop?

truncate deletes the data of the entire table;

Delete directly deletes the data corresponding to the id if the judgment condition is id, and directly deletes the data of the entire table if it is directly from the table name;

drop can be used to delete a table (drop from table name) or a database (drop from database);

Execution speed drop>truncate>delete