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https://dev.mysql.com/doc/refman/8.4/en/index-statistics.html
When a given index value yields a large number of rows, the index is less useful and MySQL is less likely to use it. This affects ref accesses for comparisons of the form tbl_name.key = expr: MySQL does not access the table if the current value of ... Storage engines collect statistics about tables for use by the ...
https://dev.mysql.com/doc/refman/8.4/en/innodb-compression-usage.html
You can set this parameter in the MySQL configuration file (my.cnf or my.ini) or dynamically, using a SET statement. Depending on the combination of option values, MySQL uses a page size of 1KB, 2KB, 4KB, 8KB, or 16KB for the tablespace data file ...
https://dev.mysql.com/doc/refman/8.4/en/innodb-locks-set.html
If you have no indexes suitable for your statement and MySQL must scan the entire table to process the statement, every row of the table becomes locked, which in turn blocks all inserts by other users to the table. LOCK TABLES sets table locks, but ... A locking read, an UPDATE, or a DELETE generally set record locks on every index record that is scanned in the processing of an SQL ...
https://dev.mysql.com/doc/refman/8.4/en/innodb-performance-optimizer-statistics.html
You can query optimizer statistics data in the mysql.innodb_table_stats and mysql.innodb_index_stats tables. You can view the last_update column of the mysql.innodb_table_stats and mysql.innodb_index_stats tables to see when statistics were last ...
https://dev.mysql.com/doc/refman/8.4/en/innodb-standard-monitor.html
Example Standard Monitor output: mysql> SHOW ENGINE INNODB STATUS\G *************************** 1. The Lock Monitor is the same as the Standard Monitor except that it includes additional lock information. Enabling either monitor for periodic output ...
https://dev.mysql.com/doc/refman/8.4/en/innodb-system-tablespace.html
The only option to achieve a smaller system tablespace is to restore your data from a backup to a new MySQL instance created with the desired system tablespace size configuration. When using a raw disk partition, ensure that the user ID that runs ...
https://dev.mysql.com/doc/refman/8.4/en/install-component.html
A component provides services that are available to the server and other components; see Section 7.5, “MySQL Components”. INSTALL COMPONENT requires the INSERT privilege for the mysql.component system table because it adds a row to that table to ...[SET variable = expr [, variable = expr] ...] variable: { {GLOBAL | @@GLOBAL.} [component_prefix.]system_var_name | {PERSIST | @@PERSIST.} [component_prefix.]system_var_name } This statement installs one or more components, which become active ...
https://dev.mysql.com/doc/refman/8.4/en/installation-layouts.html
MySQL Installation Layout on Microsoft Windows Section 2.8.3, “MySQL Layout for Source Installation” Table 2.3, “MySQL Installation Layout for Generic Unix/Linux Binary Package” Table 2.13, “MySQL Installation Layout for Linux RPM Packages ... The installation layout differs for different installation types (for example, native packages, binary tarballs, and source tarballs), which can lead to confusion when managing different systems or using different installation ...
https://dev.mysql.com/doc/refman/8.4/en/invisible-indexes.html
MySQL supports invisible indexes; that is, indexes that are not used by the optimizer. Using the SET_VAR optimizer hint to update the value of optimizer_switch temporarily, you can enable invisible indexes for the duration of a single query only, ...The feature applies to indexes other than primary keys (either explicit or ...
https://dev.mysql.com/doc/refman/8.4/en/large-page-support.html
In MySQL, large pages can be used by InnoDB, to allocate memory for its buffer pool and additional memory pool. Standard use of large pages in MySQL attempts to use the largest size supported, up to 4MB. MySQL also supports the Linux implementation ... Some hardware and operating system architectures support memory pages greater than the default (usually ...