在之前整理过一版MySQL的数据字典,整理了一圈,发现远比想象的复杂。 当然整理的过程不光是知识梳理的过程,也是转化为实践场景的一个过程,通过这样一个体系,对于整个MySQL对象生命周期管理有了较为深入的认识,这里我来抛砖引玉,来作为深入学习MySQL数据字典的一个入口,这个问题就是:如何较为准确的计算MySQL碎片情况?
lower_case_table_names=1default_authentication_plugin=mysql_native_password sql_mode='STRICT_TRANS_TABLES,NO_ZERO_IN_DATE,NO_ZERO_DATE,ERROR_FOR_DIVISION_BY_ZERO,NO_ENGINE_SUBSTITUTION'# connection # back_log=500interactive_timeout=300wait_timeout=1800lock_wait_timeout=300max_user_connections=80...
table_performance_timers, table_persisted_variables, table_plugin_table, table_prepared_stmt_instances, table_processlist, table_replication_applier_configuration, table_replication_applier_filters, table_replication_applier_global_filters, table_replication_applier_status, table_replication_applier_status_by_...
当sort_buffer_size 超过2KB的时候,就会使用mmap() 而不是 malloc() 来进行内存分配,导致效率降低。 lower_case_table_names lower_case_table_names = 1 Linux或类Unix平台,对文件名称大小写敏感,也即对数据库、表、存储过程等对象名称大小写敏 感,为减少开发人员的开发成本,为此推荐大家设置该参数使对象名称...
If you cannot avoid that function in SQL, create a new function-based index or generate custom columns in the database to improve performance. Avoid Wildcard (%) at the Beginning of Predicates Wildcards perform a broader search when searching through textual data. For example, to select all ...
lower_case_table_names=1slave.cnf:| # Apply this config only on slaves. [mysqld] super-read-only log_bin_trust_function_creators=1 MYSQL POD配置清单 apiVersion:apps/v1kind:StatefulSetmetadata:name:mysqlnamespace:mageduspec:selector:matchLabels:app:mysqlserviceName:mysqlreplicas:2template:metadata...
如果打算在升级时将lower_case_table_names设置更改为1,请在升级前确保模式名和表名为小写,否则的话 可能会由于模式或表名字母大小写不匹配而导致失败 ,查询表名字母大小写 命令如下: 1.[root@mysql.sock][(none)]>selectTABLE_NAME,if(sha(TABLE_NAME)!=sha(lower(TABLE_NAME)),'Yes','No')asUpperCase...
performance_schema = 0 explicit_defaults_for_timestamp lower_case_table_names = 1 default_storage_engine = InnoDB #default-storage-engine = MyISAM innodb_file_per_table = 1 innodb_open_files = 500 innodb_buffer_pool_size = 64M innodb_write_io_threads = 4 ...
SHOW TABLESandSELECT * FROM INFORMATION_SCHEMA.TABLESdid not return any results from the Performance Schema if the user had access privileges on individual Performance Schema tables, only. (Bug #33283709) Calling a function relating to thedata_maskingplugin without first installing the plugin led to...
线程1事务没提交,导致线程2做 DDL hang 住,访问 performance_schema.metadata_locks 可以看到是因为线程1持有 t1 的 SHARED_READ 锁,导致需要获取 EXCLUSIVE 锁的线程2处于等待状态。 mysql > SELECT * FROM performance_schema.metadata_locks; +---+---+---+---+---+---+---+---+---+---...