The BOOL or BOOLEAN datatype is used to store true/false values. Internally, it is represented as a TINYINT where 1 is true and 0 is false.

The SHOW PROCESSLIST; command displays a list of active threads and queries currently running on the MySQL server. It is useful for identifying slow or problematic queries.

The Information Schema in MySQL is a set of read-only tables that provide metadata about the database structure, such as information about tables, columns, and indexes.

Group replication is the default replication method used in a MySQL InnoDB Cluster. It provides fault tolerance and high availability by replicating transactions to all nodes and handling automatic failover in case of node failure.

MyISAM is optimized for read-heavy workloads and is a good choice for applications that do not require transactions. However, it lacks support for features like transactions and foreign keys.