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https://dev.mysql.com/doc/refman/8.4/en/innodb-compression-tuning.html
Setting the compressed page size too large wastes some space, but the pages do not have to be compressed as often. If the compressed page size is set too small, inserts or updates may require time-consuming recompression, and the B-tree nodes may ...
https://dev.mysql.com/doc/refman/8.4/en/innodb-enabling-monitors.html
Both the InnoDB Standard Monitor and InnoDB Lock Monitor must be enabled to have InnoDB Lock Monitor data printed periodically. Both the InnoDB standard Monitor and InnoDB Lock Monitor must be enabled to have InnoDB Lock Monitor data printed ...
https://dev.mysql.com/doc/refman/8.4/en/innodb-information-schema-metrics-table.html
Because no DML operations have been performed, the counter values are zero or NULL. The TIME_ENABLED and TIME_ELAPSED values indicate when the counter was last enabled and how many seconds have elapsed since that time. A number of counter values ...
https://dev.mysql.com/doc/refman/8.4/en/innodb-purge-configuration.html
The InnoDB transaction system maintains a list of transactions that have index records delete-marked by UPDATE or DELETE operations. A typical innodb_max_purge_lag setting for a problematic workload might be 1000000 (1 million), assuming that ...
https://dev.mysql.com/doc/refman/8.4/en/innodb-row-format.html
If all columns in the index are NOT NULL and have a fixed length, the record header has no variable-length part. The row format of a table determines how its rows are physically stored, which in turn can affect the performance of queries and DML ...
https://dev.mysql.com/doc/refman/8.4/en/innodb-standard-monitor.html
SEMAPHORES This section reports threads waiting for a semaphore and statistics on how many times threads have needed a spin or a wait on a mutex or a rw-lock semaphore. The contents show which transactions are involved, the statement each was ...
https://dev.mysql.com/doc/refman/8.4/en/invisible-columns.html
Although a table must have at least one visible column, an index definition need not have any visible columns. An invisible column is normally hidden to queries, but can be accessed if explicitly referenced. As an illustration of when invisible ...
https://dev.mysql.com/doc/refman/8.4/en/key-space.html
This is for the worst case when all keys are inserted in sorted order and the table doesn't have any compressed keys. Numbers are stored with the high byte first, so this helps when you have many integer keys that have an identical prefix. You can ...
https://dev.mysql.com/doc/refman/8.4/en/keyring-key-migration.html
The account used to connect to the running server must have the privileges required to modify keyring_operations. The user a server in key-migration mode runs as must have permission to read and write any local keyring files, such as the data file ... A keyring migration copies keys from one keystore to another, enabling a DBA to switch a MySQL installation to a different ...
https://dev.mysql.com/doc/refman/8.4/en/limit-optimization.html
After the initial rows have been found, MySQL does not sort any remainder of the result set. If multiple rows have identical values in the ORDER BY columns, the server is free to return those rows in any order, and may do so differently depending on ... If you need only a specified number of rows from a result set, use a LIMIT clause in the query, rather than fetching the whole result set and throwing away the extra ...