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https://dev.mysql.com/doc/refman/8.4/en/innodb-next-key-locking.html
Let the table contain rows having id values of 90 and 102. If the locks set on the index records in the scanned range do not lock out inserts made in the gaps (in this case, the gap between 90 and 102), another session can insert a new row into the ... The so-called phantom problem occurs within a transaction when the same query produces different sets of rows at different ...
https://dev.mysql.com/doc/refman/8.4/en/monitor-mysql-memory-use.html
Instruments can be enabled by updating the ENABLED column of the Performance Schema setup_instruments table. To view available MySQL memory instruments, query the Performance Schema setup_instruments table. After restarting the server, the ENABLED ... The following example demonstrates how to use Performance Schema and sys schema to monitor MySQL memory ...
https://dev.mysql.com/doc/refman/8.4/en/mrr-optimization.html
Reading rows using a range scan on a secondary index can result in many random disk accesses to the base table when the table is large and not stored in the storage engine's cache. Then the keys are sorted and finally the rows are retrieved from ...
https://dev.mysql.com/doc/refman/8.4/en/mysql-cluster-importing-data.html
You may also wish to do this when performing bulk DELETE or UPDATE operations on NDB Cluster tables. If a data import operation does not complete successfully, for whatever reason, you should be prepared to perform any necessary cleanup including ...
https://dev.mysql.com/doc/refman/8.4/en/mysql-configurator-cli.html
MySQL Configurator supports GUI (default) and CLI (by passing in --console) modes using the mysql_configurator.exe executable. CLI Syntax The general syntax is: mysql_configurator.exe --console [--help] | [--action=action_name | -a=action_name] | ...Note MySQL Configurator CLI functionality was added in MySQL Configurator ...
https://dev.mysql.com/doc/refman/8.4/en/mysql-enterprise-backup.html
The product is architected for efficient and reliable backups of tables created by the InnoDB storage engine. For completeness, it can also back up tables from MyISAM and other storage engines. MySQL Enterprise Backup does a hot backup of all tables ... MySQL Enterprise Backup performs hot backup operations for MySQL ...
https://dev.mysql.com/doc/refman/8.4/en/optimize-character.html
The GROUP BY and ORDER BY clauses can generate temporary tables, and these temporary tables can use the MEMORY storage engine if the original table does not contain any BLOB columns. If a table contains string columns such as name and address, but ... For character and string columns, follow these guidelines: Use binary collation order for fast comparison and sort operations, when you do not need language-specific collation ...
https://dev.mysql.com/doc/refman/8.4/en/partitioning-columns-list.html
See Section 15.1.20, “CREATE TABLE Statement”, for additional information about PARTITION BY LIST COLUMNS() syntax. This is a variant of LIST partitioning that enables the use of multiple columns as partition keys, and for columns of data types ...
https://dev.mysql.com/doc/refman/8.4/en/precision-math-examples.html
Consider these statements: mysql> CREATE TABLE t (i INT, d DECIMAL, f FLOAT); mysql> INSERT INTO t VALUES(1,1,1); mysql> CREATE TABLE y SELECT AVG(i), AVG(d), AVG(f) FROM t; The result is a double only for the floating-point argument. This section ...
https://dev.mysql.com/doc/refman/8.4/en/replication-howto-additionalslaves.html
You can list the events on a server using the SHOW statement or the Information Schema EVENTS table. For example, the InnoDB system tablespace, undo tablespace, and redo log might be stored in an alternative location. InnoDB tablespace files and ...