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https://dev.mysql.com/doc/internals/en/implementing-external-lock-method.html
The [custom-engine.html#custom-engine-api-reference-external_lock external_lock()] method is called at the start of a statement or when a LOCK TABLES statement is issued. Examples of using external_lock() can be found in the sql/ha_innodb.cc file, ...
https://dev.mysql.com/doc/refman/8.4/en/sql-transactional-statements.html
MySQL supports local transactions (within a given client session) through statements such as SET autocommit, START TRANSACTION, COMMIT, and ROLLBACK. XA transaction support enables MySQL to participate in distributed transactions as well.
https://dev.mysql.com/doc/refman/8.4/en/flush.html
| table_synonym WITH READ LOCK | table_synonym tbl_name [, tbl_name] ... FOR EXPORT } table_synonym: { TABLE | TABLES } The FLUSH statement has several variant forms that clear or reload various internal caches, flush tables, or acquire locks. Note ...| tables_option } flush_option: { BINARY LOGS | ENGINE LOGS | ERROR LOGS | GENERAL LOGS | LOGS | PRIVILEGES | OPTIMIZER_COSTS | RELAY LOGS [FOR CHANNEL channel] | SLOW LOGS | STATUS | USER_RESOURCES } tables_option: { table_synonym | table_synonym tbl_name [, tbl_name] ...
https://dev.mysql.com/doc/refman/8.4/en/innodb-transaction-isolation-levels.html
InnoDB supports each of the transaction isolation levels described here using different locking strategies. Or you can relax the consistency rules with READ COMMITTED or even READ UNCOMMITTED, in situations such as bulk reporting where precise ...
https://dev.mysql.com/doc/refman/8.4/en/innodb-deadlock-example.html
The following example illustrates how an error can occur when a lock request causes a deadlock. Client A enables innodb_print_all_deadlocks, creates two tables, 'Animals' and 'Birds', and inserts data into each. If client A attempts to update a row ...Thererfore, the previous read-only transaction id changes from 421291106148352 to ...
https://dev.mysql.com/doc/refman/8.4/en/innodb-auto-increment-handling.html
InnoDB provides a configurable locking mechanism that can significantly improve scalability and performance of SQL statements that add rows to tables with AUTO_INCREMENT columns. This section describes the AUTO_INCREMENT lock modes, usage ...To use ...
https://dev.mysql.com/doc/refman/8.4/en/mysqldump.html
It has the same effect as --source-data in terms of enabling or disabling other options and in how locking is handled. They also turn on --lock-all-tables, unless --single-transaction also is specified, in which case, a global read lock is acquired ... The mysqldump client utility performs logical backups, producing a set of SQL statements that can be executed to reproduce the original database object definitions and table ...
https://dev.mysql.com/doc/refman/8.4/en/server-system-variables.html
Note Some system variable descriptions include a block size, in which case a value that is not an integer multiple of the stated block size is rounded down to the next lower multiple of the block size before being stored by the server, that is to ...
https://dev.mysql.com/doc/refman/8.4/en/general-thread-states.html
If the thread is locked by some other thread, the kill takes effect as soon as the other thread releases its lock. Locking system tables The thread is trying to lock a system table (for example, a time zone or log table). For example, an ALTER TABLE ... The following list describes thread State values that are associated with general query processing and not more specialized activities such as ...
https://dev.mysql.com/doc/refman/8.4/en/innodb-online-ddl-performance.html
Reduced locking and waiting for MySQL server resources leads to greater scalability, even for operations that are not involved in the DDL operation. An exclusive metadata lock on the table may be taken briefly during the execution phase of the ...