PDF (US Ltr)
- 43.2Mb
PDF (A4)
- 43.3Mb
Man Pages (TGZ)
- 295.2Kb
Man Pages (Zip)
- 400.4Kb
Info (Gzip)
- 4.3Mb
Info (Zip)
- 4.3Mb
Search Results
https://dev.mysql.com/doc/refman/8.0/en/sys-user-summary-by-file-io-type.html
These views summarize file I/O, grouped by user and event type. By default, rows are sorted by user and descending total latency. The user_summary_by_file_io_type and x$user_summary_by_file_io_type views have these columns: user The client user ...
https://dev.mysql.com/doc/refman/8.0/en/json-attribute-functions.html
The functions in this section return attributes of JSON values. An error occurs if the argument is not a valid JSON document. An empty array, empty object, or scalar value has depth 1. A nonempty array containing only elements of depth 1 or ...
https://dev.mysql.com/doc/refman/8.0/en/innodb-performance-spin_lock_polling.html
InnoDB mutexes and rw-locks are typically reserved for short intervals. 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 sleeps. If the mutex or ...However, too-frequent polling of a shared object such as a mutex or rw-lock by multiple threads can cause “cache ping pong”, which results in processors invalidating portions of each other's ...
https://dev.mysql.com/doc/refman/8.0/en/multiple-key-caches.html
An update operation most frequently executed for temporary tables is performed much faster when the updated node is in the cache and need not be read from disk first. The CACHE INDEX statement sets up an association between a table and a key cache, ...Any attempt to do this is ignored: mysql> SET GLOBAL key_buffer_size = 0; mysql> SHOW VARIABLES LIKE 'key_buffer_size'; +-----------------+---------+ | Variable_name | Value | +-----------------+---------+ | key_buffer_size | 8384512 | +-----------------+---------+ Key cache variables are structured system variables that have a name and ...
https://dev.mysql.com/doc/refman/8.0/en/clone-plugin-concurrent-ddl.html
The clone_ddl_timeout variable defines the time in seconds on the donor and recipient that a cloning operation waits for a backup lock. Prior to MySQL 8.0.27, DDL operations on the donor and recipient MySQL Server instances, including TRUNCATE ...
https://dev.mysql.com/doc/refman/8.0/en/validate-password-installation.html
This section describes how to install and uninstall the validate_password password-validation component. Note If you install MySQL 8.0 using the MySQL Yum repository, MySQL SLES Repository, or RPM packages provided by Oracle, the validate_password ...For general information about installing and uninstalling components, see Section 7.5, “MySQL ...To be usable by the server, the component library file ...
https://dev.mysql.com/doc/refman/8.0/en/help.html
The HELP statement searches the help tables for the given search string and displays the result of the search. The search string can contain the wildcard characters % and _. If X is less than or equal to 0.0E0, the function returns NULL and a ...
https://dev.mysql.com/doc/refman/8.0/en/archive-storage-engine.html
The ARCHIVE engine supports INSERT, REPLACE, and SELECT, but not DELETE or UPDATE. It does support ORDER BY operations, BLOB columns, and spatial data types (see Section 13.4.1, “Spatial Data Types”). The ARCHIVE engine ignores BLOB columns if ... The ARCHIVE storage engine produces special-purpose tables that store large amounts of unindexed data in a very small ...
https://dev.mysql.com/doc/refman/8.0/en/group-replication-change-primary.html
If you do not set the timeout, there is no upper limit to the wait time, and new transactions can start during that time. Explicitly defined transactions (with a START TRANSACTION or BEGIN statement) are subject to the timeout, disconnection, and ...
https://dev.mysql.com/doc/refman/8.0/en/innodb-deadlocks.html
A deadlock can occur when transactions lock rows in multiple tables (through statements such as UPDATE or SELECT ... A deadlock can also occur when such statements lock ranges of index records and gaps, with each transaction acquiring some locks but ... A deadlock is a situation in which multiple transactions are unable to proceed because each transaction holds a lock that is needed by another ...