通过下面的命令我们可以查看各种sql的执行频率，'Com_xxx'代表每个xxx语句执行的次数。如下面的代码，下面一共有142行被选择。下面的参数对所有引擎的表操作都会进行累加。通常我们只关心下面几个统计参数。
- Com_select,执行select的次数，一次查询只累加1
- Com_insert执行insert的次数，对于批量插入的insert只累加1次
- Com_update执行update的次数
- Com_delete，执行delete的次数，
- Com_commit事务的提交情况
- Com_rollback事务的回滚情况
mysql> show status like 'com%';+---------------------------+-------+| Variable_name | Value |+---------------------------+-------+| Com_admin_commands | 0 || Com_assign_to_keycache | 0 || Com_alter_db | 0 || Com_alter_db_upgrade | 0 || Com_alter_event | 0 || Com_alter_function | 0 || Com_alter_procedure | 0 || Com_alter_server | 0 || Com_alter_table | 0 || Com_alter_tablespace | 0 || Com_alter_user | 0 || Com_analyze | 0 || Com_begin | 0 || Com_binlog | 0 || Com_call_procedure | 0 || Com_change_db | 0 || Com_change_master | 0 || Com_check | 0 || Com_checksum | 0 || Com_commit | 0 || Com_create_db | 0 || Com_create_event | 0 || Com_create_function | 0 || Com_create_index | 0 || Com_create_procedure | 0 || Com_create_server | 0 || Com_create_table | 0 || Com_create_trigger | 0 || Com_create_udf | 0 || Com_create_user | 0 || Com_create_view | 0 || Com_dealloc_sql | 0 || Com_delete | 0 || Com_delete_multi | 0 || Com_do | 0 || Com_drop_db | 0 || Com_drop_event | 0 || Com_drop_function | 0 || Com_drop_index | 0 || Com_drop_procedure | 0 || Com_drop_server | 0 || Com_drop_table | 0 || Com_drop_trigger | 0 || Com_drop_user | 0 || Com_drop_view | 0 || Com_empty_query | 0 || Com_execute_sql | 0 || Com_flush | 0 || Com_get_diagnostics | 0 || Com_grant | 0 || Com_ha_close | 0 || Com_ha_open | 0 || Com_ha_read | 0 || Com_help | 0 || Com_insert | 0 || Com_insert_select | 0 || Com_install_plugin | 0 || Com_kill | 0 || Com_load | 0 || Com_lock_tables | 0 || Com_optimize | 0 || Com_preload_keys | 0 || Com_prepare_sql | 0 || Com_purge | 0 || Com_purge_before_date | 0 || Com_release_savepoint | 0 || Com_rename_table | 0 || Com_rename_user | 0 || Com_repair | 0 || Com_replace | 0 || Com_replace_select | 0 || Com_reset | 0 || Com_resignal | 0 || Com_revoke | 0 || Com_revoke_all | 0 || Com_rollback | 0 || Com_rollback_to_savepoint | 0 || Com_savepoint | 0 || Com_select | 1 || Com_set_option | 0 || Com_signal | 0 || Com_show_binlog_events | 0 || Com_show_binlogs | 0 || Com_show_charsets | 0 || Com_show_collations | 0 || Com_show_create_db | 0 || Com_show_create_event | 0 || Com_show_create_func | 0 || Com_show_create_proc | 0 || Com_show_create_table | 0 || Com_show_create_trigger | 0 || Com_show_databases | 0 || Com_show_engine_logs | 0 || Com_show_engine_mutex | 0 || Com_show_engine_status | 0 || Com_show_events | 0 || Com_show_errors | 0 || Com_show_fields | 0 || Com_show_function_code | 0 || Com_show_function_status | 0 || Com_show_grants | 0 || Com_show_keys | 0 || Com_show_master_status | 0 || Com_show_open_tables | 0 || Com_show_plugins | 0 || Com_show_privileges | 0 || Com_show_procedure_code | 0 || Com_show_procedure_status | 0 || Com_show_processlist | 0 || Com_show_profile | 0 || Com_show_profiles | 0 || Com_show_relaylog_events | 0 || Com_show_slave_hosts | 0 || Com_show_slave_status | 0 || Com_show_status | 1 || Com_show_storage_engines | 0 || Com_show_table_status | 0 || Com_show_tables | 0 || Com_show_triggers | 0 || Com_show_variables | 0 || Com_show_warnings | 0 || Com_slave_start | 0 || Com_slave_stop | 0 || Com_stmt_close | 0 || Com_stmt_execute | 0 || Com_stmt_fetch | 0 || Com_stmt_prepare | 0 || Com_stmt_reprepare | 0 || Com_stmt_reset | 0 || Com_stmt_send_long_data | 0 || Com_truncate | 0 || Com_uninstall_plugin | 0 || Com_unlock_tables | 0 || Com_update | 0 || Com_update_multi | 0 || Com_xa_commit | 0 || Com_xa_end | 0 || Com_xa_prepare | 0 || Com_xa_recover | 0 || Com_xa_rollback | 0 || Com_xa_start | 0 || Compression | OFF |+---------------------------+-------+142 rows in set (0.00 sec)
对于InnoDB我们还应该查询下面的参数
mysql> show status like 'Innodb_rows%';+----------------------+-------+| Variable_name | Value |+----------------------+-------+| Innodb_rows_deleted | 1 || Innodb_rows_inserted | 49 || Innodb_rows_read | 81 || Innodb_rows_updated | 0 |+----------------------+-------+4 rows in set (0.00 sec)
- Innodb_rows_read:select 查询返回的行数
- Innodb_rows_inserted:执行insert插入的行数
- Innodb_rows_updated执行update更新的行数
- Innodb_rows_deleted执行delete删除的行数
同时我们还可以通过Connections了解试图连接MySQL的次数，Uptime服务器工作时间，Slow_queries慢查询的次数。