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https://dev.mysql.com/doc/refman/8.4/en/innodb-buffer-pool.html
A table scan, performed for a mysqldump operation or a SELECT statement with no WHERE clause, for example, can bring a large amount of data into the buffer pool and evict an equivalent amount of older data, even if the new data is never used again.
https://dev.mysql.com/doc/refman/8.4/en/innodb-check-availability.html
Issue a SHOW ENGINES statement to view the available MySQL storage engines.
https://dev.mysql.com/doc/refman/8.4/en/innodb-compression-internals.html
This section describes some internal implementation details about compression for InnoDB tables. The information presented here may be helpful in tuning for performance, but is not necessary to know for basic use of compression. Compression ...
https://dev.mysql.com/doc/refman/8.4/en/innodb-file-defragmenting.html
Another symptom of fragmentation is that a table scan such as this takes more time than it “should” take: SELECT COUNT(*) FROM t WHERE non_indexed_column <> 12345; The preceding query requires MySQL to perform a full table scan, the slowest type ... Random insertions into or deletions from a secondary index can cause the index to become ...
https://dev.mysql.com/doc/refman/8.4/en/innodb-information-schema-understanding-innodb-locking.html
When a transaction updates a row in a table, or locks it with SELECT FOR UPDATE, InnoDB establishes a list or queue of locks on that row. Similarly, InnoDB maintains a list of locks on a table for table-level locks. If a second transaction wants to ...
https://dev.mysql.com/doc/refman/8.4/en/innodb-moving-data-files-offline.html
To view tablespace file locations, query the Information Schema FILES table: mysql> SELECT TABLESPACE_NAME, FILE_NAME FROM INFORMATION_SCHEMA.FILES \G . The innodb_directories variable, which defines directories to scan at startup for tablespace ...
https://dev.mysql.com/doc/refman/8.4/en/innodb-purge-configuration.html
Running a SELECT query after disabling autocommit, and forgetting to issue an explicit COMMIT or ROLLBACK. InnoDB does not physically remove a row from the database immediately when you delete it with an SQL statement. A row and its index records ...
https://dev.mysql.com/doc/refman/8.4/en/innodb-troubleshooting-datadict.html
mysql> SELECT COUNT(*) FROM sakila.actor; +----------+ | count(*) | +----------+ | 200 | +----------+ . Information about table definitions is stored in the InnoDB data dictionary. If you move data files around, dictionary data can become ...
https://dev.mysql.com/doc/refman/8.4/en/ipv6-local-connections.html
mysql> SELECT CURRENT_USER(), @@bind_address; +----------------+----------------+ | CURRENT_USER() | @@bind_address | +----------------+----------------+ | ipv6user@::1 | :: | +----------------+----------------+ . The following procedure shows how ...
https://dev.mysql.com/doc/refman/8.4/en/ipv6-remote-connections.html
mysql> SELECT CURRENT_USER(), @@bind_address; +-----------------------------------+----------------+ | CURRENT_USER() | @@bind_address | +-----------------------------------+----------------+ | remoteipv6user@2001:db8:0:f101::2 | :: | ... The ...