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https://dev.mysql.com/doc/refman/8.4/en/server-options.html
It also causes OPTIMIZE TABLE to be mapped to ALTER TABLE for storage engines for which OPTIMIZE TABLE is not supported. The server executable determines its own full path name at startup and uses the parent of the directory in which it is located ... When you start the mysqld server, you can specify program options using any of the methods described in Section 6.2.2, “Specifying Program ...
https://dev.mysql.com/doc/heatwave/en/mys-hw-auto-parallel-load.html
| | Sufficient HeatWave cluster memory available to load all tables. If Auto Parallel Load fails with an error, inspect the errors with a query to the heatwave_autopilot_report table. mysql> SELECT log FROM sys.heatwave_autopilot_report WHERE ...
https://dev.mysql.com/doc/refman/8.4/en/invisible-columns.html
As an illustration of when invisible columns may be useful, suppose that an application uses SELECT * queries to access a table, and must continue to work without modification even if the table is altered to add a new column that the application ...
https://dev.mysql.com/doc/refman/8.4/en/performance-schema-stage-tables.html
During execution of an ALTER TABLE statement, the stage/sql/copy to tmp table stage is used, and this stage can execute potentially for a long time, depending on the size of the data to copy. To enable the instrument and the relevant consumers, ...
https://dev.mysql.com/doc/refman/8.4/en/myisamchk.html
The myisamchk utility gets information about your database tables or checks, repairs, or optimizes them. myisamchk works with MyISAM tables (tables that have .MYD and .MYI files for storing data and indexes). You can also use the CHECK TABLE and ...
https://dev.mysql.com/doc/refman/8.4/en/innodb-online-ddl-performance.html
Transactions started before or during the DDL operation can hold metadata locks on the table being altered. Session 2: mysql> ALTER TABLE t1 ADD COLUMN x INT, ALGORITHM=INPLACE, LOCK=NONE; The online DDL operation in session 2, which requires an ...
https://dev.mysql.com/doc/refman/8.4/en/load-xml.html
To write data from a table to an XML file, you can invoke the mysql client with the --xml and -e options from the system shell, as shown here: $> mysql --xml -e 'SELECT * FROM mydb.mytable' > file.xml To read the file back into a table, use LOAD XML. By default, the <row> element is considered to be the equivalent of a database table row; this can be changed using the ROWS IDENTIFIED BY ...
https://dev.mysql.com/doc/refman/8.4/en/mysql-cluster-online-add-node-example.html
In addition, for each table, the ALTER TABLE statement should be followed by an OPTIMIZE TABLE to reclaim wasted space. However, in NDBCLUSTER tables that existed prior to the addition of the new nodes, neither existing nor new data is distributed ...You can verify that all existing data nodes were restarted using the updated configuration by checking the ndbinfo.nodes table in the mysql ... In this section we provide a detailed example illustrating how to add new NDB Cluster data nodes ...
https://dev.mysql.com/doc/relnotes/mysql/8.4/en/news-8-4-0.html
In this release, the use of any such columns in the proposed partitioning key is now expressly disallowed, and causes the CREATE TABLE or ALTER TABLE statement in which it occurs to be rejected with an error. Attempting to use these together in ...
https://dev.mysql.com/doc/refman/8.4/en/innodb-compression-tuning.html
\! ls -l data/test/big_table.ibd CREATE TABLE key_block_size_4 LIKE big_table; ALTER TABLE key_block_size_4 key_block_size=4 row_format=compressed; INSERT INTO key_block_size_4 SELECT * FROM big_table; commit; -- Check how much space is needed for a ...However, because the efficiency of compression depends on the nature of your data, you can make decisions that affect the performance of compressed tables: Which tables to ...