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https://dev.mysql.com/doc/refman/8.4/en/show-profile.html
For example, SHOW PROFILING is an illegal statement, and a syntax error occurs if you try to execute it, but it shows up in the profiling list. Without the FOR QUERY n clause, the output pertains to the most recently executed statement. Note The ...
https://dev.mysql.com/doc/refman/8.4/en/user-variables.html
A reference to a user variable in a prepared statement has its type determined when the statement is first prepared, and retains this type each time the statement is executed thereafter. Similarly, the type of a user variable employed in a statement ... You can store a value in a user-defined variable in one statement and refer to it later in another ...
https://dev.mysql.com/doc/refman/8.4/en/cost-model.html
To generate execution plans, the optimizer uses a cost model that is based on estimates of the cost of various operations that occur during query execution. The optimizer has a set of compiled-in default “cost constants” available to it to make ...Any non-NULL cost estimate specified in the tables takes precedence over the corresponding compiled-in default cost ...
https://dev.mysql.com/doc/internals/en/optimizer-definitions.html
This description uses a narrow definition: The optimizer is the set of routines which decide what execution path the DBMS should take for queries. MySQL changes these routines frequently, so you should compare what is said here with what's in the ...
https://dev.mysql.com/doc/x-devapi-userguide-shell-js/en/collections-as-relational-tables.html
Applications that seek to store standard SQL columns with Documents can cast a collection to a table. In this case a collection can be fetched as a Table object with the Schema.getCollectionAsTable() function. From that moment on it is treated as a ...
https://dev.mysql.com/doc/x-devapi-userguide-shell-python/en/collections-as-relational-tables.html
# Get the customers collection as a table customers = db.get_collection_as_table('customers') customers.insert('doc').values('{"_id":"001", "name": "Ana", "last_name": "Silva"}').execute() # Now do a find operation to retrieve the inserted document ... Applications that seek to store standard SQL columns with Documents can cast a collection to a ...
https://dev.mysql.com/doc/refman/8.4/en/group-replication-requirements.html
Transactions are executed optimistically and then, at commit time, are checked for conflicts. The use of other storage engines, including the temporary MEMORY storage engine, might cause errors in Group Replication. Bi-directional communication must ... Infrastructure Server Instance Configuration Server instances that you want to use for Group Replication must satisfy the following ...
https://dev.mysql.com/doc/ndbapi/en/ndb-event.html
The new version of the API also simplifies error detection and handling. Old (deprecated) methods are shown in the first column of the following table, and new methods in the second column; old methods corresponding to new methods are shown in the ...Event Class Overview Event::addEventColumn() Event::addEventColumns() Event::addTableEvent() Event Constructor Event::EventDurability Event::EventReport Event::getDurability() Event::getEventColumn() Event::getName() Event::getNoOfEventColumns() Event::getObjectStatus() Event::getObjectVersion() Event::getObjectId() Event::getReport() Event::getTable() Event::getTableEvent() Event::getTableName() Event::mergeEvents() Event::setDurability() Event::setReport() Event::setName() Event::setTable() Event::TableEvent Event Class Overview Parent class NdbDictionary Child classes None Description This class represents a database event in an NDB ...
https://dev.mysql.com/doc/mysql-em-plugin/en/myoem-compliance-performance-standard-rules.html
In the event of a crash, if you can afford to lose a second's worth of transactions, you can achieve better performance by setting innodb_flush_log_at_trx_commit to either 0 or 2. If you set the value to 2, then only an operating system crash or a ... The following are the MySQL Performance Standard compliance rules: InnoDB Flush Method May Not Be Optimal InnoDB Log Buffer Flushed To Disk After Each Transaction InnoDB Flush Method May Not Be Optimal Description Different values for innodb_flush_method can have a marked effect on InnoDB ...
https://dev.mysql.com/doc/refman/8.4/en/multifactor-authentication.html
Authentication involves one party establishing its identity to the satisfaction of a second party. The default authentication_policy value is '*,,' (an asterisk and two empty elements), which requires a first factor, and optionally permits second ...Multifactor authentication (MFA) is the use of multiple authentication values (or “factors”) during the authentication ...