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https://dev.mysql.com/doc/refman/8.4/en/innodb-moving-data-files-offline.html
The innodb_directories variable, which defines directories to scan at startup for tablespace files, supports moving or restoring tablespace files to a new location while the server is offline. During startup, discovered tablespace files are used ...
https://dev.mysql.com/doc/refman/8.4/en/innodb-recovery.html
In some cases of database corruption, it is enough to dump, drop, and re-create one or a few corrupt tables. You can use the CHECK TABLE statement to check whether a table is corrupt, although CHECK TABLE naturally cannot detect every possible kind ...To achieve point-in-time recovery after restoring a backup, you can apply changes from the binary log that occurred after the backup was ...
https://dev.mysql.com/doc/refman/8.4/en/kerberos-pluggable-authentication.html
Kerberos pluggable authentication provides these capabilities: External authentication: Kerberos authentication enables MySQL Server to accept connections from users defined outside the MySQL grant tables who have obtained the proper Kerberos ...
https://dev.mysql.com/doc/refman/8.4/en/nested-loop-joins.html
MySQL executes joins between tables using a nested-loop algorithm or variations on it. Nested-Loop Join Algorithm Nested-Loop Join Algorithm A simple nested-loop join (NLJ) algorithm reads rows from the first table in a loop one at a time, passing ...
https://dev.mysql.com/doc/refman/8.4/en/optimizing-innodb-diskio.html
Increase buffer pool size When table data is cached in the InnoDB buffer pool, it can be accessed repeatedly by queries without requiring any disk I/O. Do not place other MySQL data files, such as those for MyISAM tables, on a direct I/O file system. Executables or libraries must not be placed on a direct I/O file ... If you follow best practices for database design and tuning techniques for SQL operations, but your database is still slow ...
https://dev.mysql.com/doc/refman/8.4/en/performance-schema-timing.html
For example, the standard gettimeofday() function can take hundreds of cycles, which is an unacceptable overhead for data gathering that may occur thousands or millions of times per second. Performance Schema Timer Representation in Events Rows in ... Events are collected by means of instrumentation added to the server source ...
https://dev.mysql.com/doc/refman/8.4/en/replication-features-reserved-words.html
For example, a table column named rank on a MySQL 5.7 source that is replicating to a MySQL 8.4 replica could cause a problem because RANK became a reserved word in MySQL 8.0. Replication can fail in such cases with Error 1064 You have an error in ... You can encounter problems when you attempt to replicate from an older source to a newer replica and you make use of identifiers on the source that are reserved words in the newer MySQL version running on the ...
https://dev.mysql.com/doc/refman/8.4/en/secure-client-programming.html
If an application generates a query such as SELECT * FROM table WHERE ID=234 when a user enters the value 234, the user can enter the value 234 OR 1=1 to cause the application to generate the query SELECT * FROM table WHERE ID=234 OR 1=1. As a ...
https://dev.mysql.com/doc/mysql-enterprise-backup/8.4/en/meb-encrypted-innodb.html
For details on how the MySQL server encrypts and decrypts InnoDB tablespaces, see InnoDB Data-at-Rest Encryption—it explains concepts like master key and tablespace keys, which are important for understanding how MySQL Enterprise Backup works with ...Notes Since the keyring_file and the keyring_encrypted_file plugins have been removed from the MySQL Server since release 8.4.0, they are no longer supported by MySQL Enterprise ...
https://dev.mysql.com/doc/refman/8.4/en/mysql-cluster-programs-ndbd.html
The ndbd binary provides the single-threaded version of the process that is used to handle all the data in tables employing the NDBCLUSTER storage engine. Options that can be used with ndbd are shown in the following table. The option also causes ...This data node process enables a data node to accomplish distributed transaction handling, node recovery, checkpointing to disk, online backup, and related ...