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https://dev.mysql.com/doc/refman/8.4/en/online-ddl-parallel-thread-configuration.html
The default setting is calculated by the number of available logical processors on the system divided by 8, with a minimum default value of 4. The maximum setting is 256, which is the maximum number for all sessions. The actual number of threads ...
https://dev.mysql.com/doc/refman/8.4/en/optimize-blob.html
When storing a large blob containing textual data, consider compressing it first. Do not use this technique when the entire table is compressed by InnoDB or MyISAM. For a table with several columns, to reduce memory requirements for queries that do ...
https://dev.mysql.com/doc/refman/8.4/en/optimize-character.html
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 features. You can use the BINARY operator to use binary collation within ...
https://dev.mysql.com/doc/refman/8.4/en/optimize-multi-tables.html
Some techniques for keeping individual queries fast involve splitting data across many tables. When the number of tables runs into the thousands or even millions, the overhead of dealing with all these tables becomes a new performance consideration.
https://dev.mysql.com/doc/refman/8.4/en/optimizer-statistics.html
The column_statistics data dictionary table stores histogram statistics about column values, for use by the optimizer in constructing query execution plans. The column_statistics table has these characteristics: The table contains statistics for ...
https://dev.mysql.com/doc/refman/8.4/en/optimizing-innodb-configuration-variables.html
Different settings work best for servers with light, predictable loads, versus servers that are running near full capacity all the time, or that experience spikes of high activity. Because the InnoDB storage engine performs many of its ...
https://dev.mysql.com/doc/refman/8.4/en/optimizing-innodb-many-tables.html
If you have configured non-persistent optimizer statistics (a non-default configuration), InnoDB computes index cardinality values for a table the first time that table is accessed after startup, instead of storing such values in the table. This ...
https://dev.mysql.com/doc/refman/8.4/en/option-modifiers.html
Some options are “boolean” and control behavior that can be turned on or off. For example, the mysql client supports a --column-names option that determines whether or not to display a row of column names at the beginning of query results.
https://dev.mysql.com/doc/refman/8.4/en/order-by-optimization.html
This section describes when MySQL can use an index to satisfy an ORDER BY clause, the filesort operation used when an index cannot be used, and execution plan information available from the optimizer about ORDER BY. An ORDER BY with and without ...
https://dev.mysql.com/doc/refman/8.4/en/other-vendor-data-types.html
To facilitate the use of code written for SQL implementations from other vendors, MySQL maps data types as shown in the following table. These mappings make it easier to import table definitions from other database systems into MySQL. If you create ...