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https://dev.mysql.com/doc/refman/8.4/en/metadata-locking.html
MySQL uses metadata locking to manage concurrent access to database objects and to ensure data consistency. Metadata locking does involve some overhead, which increases as query volume increases. Metadata contention increases the more that multiple ...Metadata locking applies not just to tables, but also to schemas, stored programs (procedures, functions, triggers, scheduled events), tablespaces, user locks acquired with the GET_LOCK() function (see Section 14.14, “Locking Functions”), and locks acquired with the locking service described in Section 7.6.9.1, “The Locking ...
https://dev.mysql.com/doc/refman/8.4/en/myisam-crash-recovery.html
If you use myisamchk to repair or optimize tables, you must always ensure that the mysqld server is not using the table (this also applies if external locking is disabled). This section describes how to check for and deal with data corruption in ...
https://dev.mysql.com/doc/refman/8.4/en/mysql-cluster-params-mgmd.html
For detailed descriptions and other additional information about each of these parameters, see Section 25.4.3.5, “Defining an NDB Cluster Management Server”. NodeId: Number uniquely identifying management node among all nodes in cluster. The ...
https://dev.mysql.com/doc/refman/8.4/en/mysqldumpslow.html
The MySQL slow query log contains information about queries that take a long time to execute (see Section 7.4.5, “The Slow Query Log”). mysqldumpslow parses MySQL slow query log files and summarizes their contents. Normally, mysqldumpslow ...It ...
https://dev.mysql.com/doc/refman/8.4/en/optimizing-innodb-transaction-management.html
The default MySQL setting AUTOCOMMIT=1 can impose performance limitations on a busy database server. To optimize InnoDB transaction processing, find the ideal balance between the performance overhead of transactional features and the workload of ...
https://dev.mysql.com/doc/refman/8.4/en/performance-schema-memory-model.html
The buffers are global to the server, so the instruments are displayed only in the memory_summary_global_by_event_name table, and not in other memory_summary_by_xxx_by_event_name tables. This query shows the information associated with the memory ...
https://dev.mysql.com/doc/refman/8.4/en/replication-binlog-encryption-scope.html
Existing binary log files and relay log files that were present on the server when you started encryption are not encrypted. Data in motion in the replication event stream, which is sent to MySQL clients including mysqlbinlog, is decrypted for ...
https://dev.mysql.com/doc/refman/8.4/en/replication-implementation.html
Replication is based on the source server keeping track of all changes to its databases (updates, deletes, and so on) in its binary log. The binary log serves as a written record of all events that modify database structure or content (data) from ...Typically, SELECT statements are not recorded because they modify neither database structure nor ...
https://dev.mysql.com/doc/refman/8.4/en/replication-mode-change-online-concepts.html
The modes of replication available in MySQL rely on different techniques for identifying logged transactions. Before setting the replication mode of an online server, it is important to understand some key concepts of replication. This section ...
https://dev.mysql.com/doc/refman/8.4/en/replication-privilege-checks-recover.html
You can use mysqlbinlog to retrieve and display the events that were logged around the time of the error. If the PRIVILEGE_CHECKS_USER account should have been permitted to execute the transaction, but has been misconfigured, grant the missing ...