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https://dev.mysql.com/doc/refman/8.4/en/preface.html
Access to Oracle Support for Accessibility Oracle customers that have purchased support have access to electronic support through My Oracle Support. This is the Reference Manual for the MySQL Database System, for the 8.4.6 LTS release. This manual ...
https://dev.mysql.com/doc/refman/8.4/en/prepare.html
As a workaround, refer instead to user-defined variables, which also have session scope; see Section 11.4, “User-Defined Variables”. (In this case, an implicit CAST(? AS derived_type) is performed.) The derived type and actual type of the ...
https://dev.mysql.com/doc/refman/8.4/en/privilege-changes.html
If you modify the grant tables directly using statements such as INSERT, UPDATE, or DELETE (which is not recommended), the changes have no effect on privilege checking until you either tell the server to reload the tables or restart it. Thus, if you ... If the mysqld server is started without the --skip-grant-tables option, it reads all grant table contents into memory during its startup ...
https://dev.mysql.com/doc/refman/8.4/en/problems-with-null.html
You can add an index on a column that can have NULL values if you are using the MyISAM, InnoDB, or MEMORY storage engine. The concept of the NULL value is a common source of confusion for newcomers to SQL, who often think that NULL is the same ...
https://dev.mysql.com/doc/refman/8.4/en/range-optimization.html
The optimizer estimates the cost of reading qualifying rows for equality range comparisons as follows: If there is a unique index on col_name, the row estimate for each range is 1 because at most one row can have the given value. Each pair of dives ... The range access method uses a single index to retrieve a subset of table rows that are contained within one or several index value ...
https://dev.mysql.com/doc/refman/8.4/en/regexp.html
If the arguments have different character sets or collations, coercibility rules apply as described in Section 12.8.4, “Collation Coercibility in Expressions”. Any character that does not have a defined special meaning inside a [] pair matches ...This section discusses the functions and operators available for regular expression matching and illustrates, with examples, some of the special characters and constructs that can be used for regular expression ...
https://dev.mysql.com/doc/refman/8.4/en/rename-user.html
To use RENAME USER, you must have the global CREATE USER privilege, or the UPDATE privilege for the mysql system schema. (That is, the statement fails if renaming an account would cause a stored object to become orphaned.) To perform the operation ... RENAME USER old_user TO new_user [, old_user TO new_user] ...
https://dev.mysql.com/doc/refman/8.4/en/replica-io-thread-states.html
If the incompatible changes have an impact for you, set the terminology_use_previous system variable to BEFORE_8_0_26 to make MySQL Server use the old versions of the names for the objects specified in the previous list. Waiting for the slave SQL ...
https://dev.mysql.com/doc/refman/8.4/en/replica-logs-relaylog.html
Relay log files have the same format as binary log files and can be read using mysqlbinlog (see Section 6.6.9, “mysqlbinlog — Utility for Processing Binary Log Files”). For the default replication channel, relay log file names have the default ... The relay log, like the binary log, consists of a set of numbered files containing events that describe database changes, and an index file that contains the names of all used relay log ...
https://dev.mysql.com/doc/refman/8.4/en/replication-asynchronous-connection-failover-replica.html
Because the sources do not have to be in a managed group, you can set up the function to synchronize a group of receivers with one or more alternative standalone senders, or even a single sender. Asynchronous connection failover for replicas is ...