PDF (US Ltr)
- 43.3Mb
PDF (A4)
- 43.4Mb
Man Pages (TGZ)
- 297.2Kb
Man Pages (Zip)
- 402.4Kb
Info (Gzip)
- 4.3Mb
Info (Zip)
- 4.3Mb
Search Results
https://dev.mysql.com/doc/refman/8.0/en/innodb-performance-spin_lock_polling.html
They can be specified in a MySQL option file or modified at runtime using a SET GLOBAL statement. On a multi-core system, it can be more efficient for a thread to continuously check if it can acquire a mutex or rw-lock for a period of time before it ... InnoDB mutexes and rw-locks are typically reserved for short ...
https://dev.mysql.com/doc/refman/8.0/en/performance-schema-replication-applier-status-by-worker-table.html
Before MySQL 8.0.13, this timestamp was refreshed when a transaction was retried due to a transient error, so it showed the timestamp for the most recent attempt to apply the transaction. The applier threads on a multithreaded replica are sometimes ... This table provides details of the transactions handled by applier threads on a replica or Group Replication group ...
https://dev.mysql.com/doc/refman/8.0/en/performance-schema-startup-configuration.html
To use the MySQL Performance Schema, it must be enabled at server startup to enable event collection to occur. For example, use these lines in the server my.cnf file: [mysqld] performance_schema=ON If the server is unable to allocate any internal ...To enable or disable it explicitly, start the server with the performance_schema variable set to an appropriate ...
https://dev.mysql.com/doc/refman/8.0/en/thread-pool-operation.html
thread_pool_prio_kickup_timer: How long before the thread pool moves a statement awaiting execution from the low-priority queue to the high-priority queue. Consider increasing the value if you experience slower response times due to long-running ...
https://dev.mysql.com/doc/refman/8.0/en/checksum-table.html
For example, the storage format for temporal types such as TIME, DATETIME, and TIMESTAMP changed in MySQL 5.6 prior to MySQL 5.6.5, so if a 5.5 table is upgraded to MySQL 5.6, the checksum value may change. For large tables, this could take a long ...[QUICK | EXTENDED] CHECKSUM TABLE reports a checksum for the contents of a ...
https://dev.mysql.com/doc/refman/8.0/en/clone-plugin-concurrent-ddl.html
Prior to MySQL 8.0.27, DDL operations on the donor and recipient MySQL Server instances, including TRUNCATE TABLE, are not permitted during a cloning operation. The clone_ddl_timeout variable defines the time in seconds on the donor and recipient ...A workaround is to use dedicated donor instances, which can accommodate DDL operations being blocked while data is ...
https://dev.mysql.com/doc/refman/8.0/en/host-cache.html
For example, to set the size to 100 at startup, put these lines in the server my.cnf file: [mysqld] host_cache_size=200 To change the size to 300 at runtime, do this: SET GLOBAL host_cache_size=300; Setting host_cache_size to 0, either at server ...
https://dev.mysql.com/doc/refman/8.0/en/innodb-benefits.html
InnoDB tables have the following benefits: If the server unexpectedly exits because of a hardware or software issue, regardless of what was happening in the database at the time, you don't need to do anything special after restarting the database.
https://dev.mysql.com/doc/refman/8.0/en/myisamchk-general-options.html
This option is available only if MySQL was built using WITH_DEBUG. MySQL release binaries provided by Oracle are not built using this option. If you are running mysqld with external locking disabled, the table can be locked only by another myisamchk ... The options described in this section can be used for any type of table maintenance operation performed by ...
https://dev.mysql.com/doc/refman/8.0/en/performance-schema-data-locks-table.html
Example data lock information: mysql> SELECT * FROM performance_schema.data_locks\G *************************** 1. Use the data_locks table to help diagnose performance problems that occur during times of heavy concurrent load. Lock ID formats are ...For information about which lock requests are blocked by which held locks, see Section 29.12.13.2, “The data_lock_waits ...