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https://dev.mysql.com/doc/refman/8.0/en/mysql-indexes.html
Most MySQL indexes (PRIMARY KEY, UNIQUE, INDEX, and FULLTEXT) are stored in B-trees. To find the MIN() or MAX() value for a specific indexed column key_col. This is optimized by a preprocessor that checks whether you are using WHERE key_part_N = ...
https://dev.mysql.com/doc/refman/8.0/en/partitioning-subpartitions.html
Note SUBPARTITION BY HASH and SUBPARTITION BY KEY generally follow the same syntax rules as PARTITION BY HASH and PARTITION BY KEY, respectively. An exception to this is that SUBPARTITION BY KEY (unlike PARTITION BY KEY) does not currently support a ... Subpartitioning—also known as composite partitioning—is the further division of each partition in a partitioned ...
https://dev.mysql.com/doc/refman/8.0/en/update.html
Each value can be given as an expression, or the keyword DEFAULT to set a column explicitly to its default value. Rows for which duplicate-key conflicts occur on a unique key value are not updated. If you use a multiple-table UPDATE statement ...
https://dev.mysql.com/doc/refman/8.0/en/macos-installation-launchd.html
macOS uses launch daemons to automatically start, stop, and manage processes and applications such as MySQL. The md5 checksum of a file containing the above snippet is d925f05f6d1b6ee5ce5451b596d6baed. To enable the launchd service, you can either: ...
https://dev.mysql.com/doc/refman/8.0/en/atomic-ddl.html
On storage engines that support both atomic DDL and foreign key constraints, creation of foreign keys is not permitted in CREATE TABLE ... An atomic DDL statement combines the data dictionary updates, storage engine operations, and binary log writes ...
https://dev.mysql.com/doc/refman/8.0/en/create-table-generated-columns.html
Generated column definitions have this syntax: col_name data_type [GENERATED ALWAYS] AS (expr) [VIRTUAL | STORED] [NOT NULL | NULL] [UNIQUE [KEY]] [[PRIMARY] KEY] [COMMENT 'string'] AS (expr) indicates that the column is generated and defines the ...
https://dev.mysql.com/doc/refman/8.0/en/innodb-memcached-benefits.html
The way InnoDB does fast primary key lookups is a natural fit for memcached single-item queries. The direct, low-level database access path used by the daemon_memcached plugin is much more efficient for key-value lookups than equivalent SQL queries.
https://dev.mysql.com/doc/refman/8.0/en/innodb-memcached-replication.html
Use the set command to insert a record with a key of test1, a flag value of 10, an expiration value of 0, a cas value of 1, and a value of t1. The example record with a key of AA, and the record you just inserted, with a key of test1. The c1 column ... Because the daemon_memcached plugin supports the MySQL binary log, source server through the memcached interface can be replicated for backup, balancing intensive read workloads, and high ...
https://dev.mysql.com/doc/refman/8.0/en/innodb-standard-monitor.html
LATEST FOREIGN KEY ERROR This section provides information about the most recent foreign key constraint error. The Lock Monitor is the same as the Standard Monitor except that it includes additional lock information. Enabling either monitor for ...
https://dev.mysql.com/doc/refman/8.0/en/mrr-optimization.html
With the Disk-Sweep Multi-Range Read (MRR) optimization, MySQL tries to reduce the number of random disk access for range scans by first scanning the index only and collecting the keys for the relevant rows. Then the keys are sorted and finally the ... Reading rows using a range scan on a secondary index can result in many random disk accesses to the base table when the table is large and not stored in the storage engine's ...