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https://dev.mysql.com/doc/heatwave/en/mys-hwaml-ml-explain-table.html
The output table includes a primary key: If the input table has a primary key, the output table will have the same primary key. If the input table does not have a primary key, the output table will have a new primary key column that auto increments.
https://dev.mysql.com/doc/heatwave/en/mys-hwaml-ml-train.html
As of MySQL 9.4.1, at least one column must act as the primary key to establish the temporal order of logs. If the primary key column (or columns) is not one of the previous required columns (log data, source of log, or label), then you must use the ... Run the ML_TRAIN routine on a training dataset to produce a trained machine learning ...
https://dev.mysql.com/doc/connector-j/en/connector-j-usagenotes-last-insert-id.html
getGeneratedKeys() is the preferred method to use if you need to retrieve AUTO_INCREMENT keys and through JDBC; this is illustrated in the first example below. On the other hand, the getGeneratedKeys() method is scoped by the Statement instance, so ...The second example shows how you can retrieve the same value using a standard SELECT LAST_INSERT_ID() ...
https://dev.mysql.com/doc/refman/8.4/en/explain.html
In practice, the DESCRIBE keyword is more often used to obtain information about table structure, whereas EXPLAIN is used to obtain a query execution plan (that is, an explanation of how MySQL would execute a query). The following discussion uses ...
https://dev.mysql.com/doc/refman/8.4/en/group-by-functional-dependence.html
A UNIQUE index over a NOT NULL column could be used instead of a primary key and the same functional dependence would apply. As with the previous example, a UNIQUE key over NOT NULL columns could be used instead of a primary key. In each case, this ... The following discussion provides several examples of the ways in which MySQL detects functional ...
https://dev.mysql.com/doc/refman/8.4/en/index-extensions.html
InnoDB automatically extends each secondary index by appending the primary key columns to it. Consider this table definition: CREATE TABLE t1 ( i1 INT NOT NULL DEFAULT 0, i2 INT NOT NULL DEFAULT 0, d DATE DEFAULT NULL, PRIMARY KEY (i1, i2), INDEX ...It also defines a secondary index k_d on column (d), but internally InnoDB extends this index and treats it as columns (d, i1, ...
https://dev.mysql.com/doc/refman/8.4/en/innodb-analyze-table-complexity.html
For example, columns a and b are counted for the primary key index. For the nonunique indexes, the primary key columns (a,b) are counted in addition to the user defined columns. ANALYZE TABLE complexity for InnoDB tables is dependent on: The number ...
https://dev.mysql.com/doc/refman/8.4/en/innodb-persistent-stats.html
The number of columns in the table's primary key is also important to consider, as primary key columns are appended to each nonunique index. Note For nonunique indexes, InnoDB appends the columns of the primary key. Only two columns are defined for ... The persistent optimizer statistics feature improves plan stability by storing statistics to disk and making them persistent across server restarts so that the optimizer is more likely to make consistent choices each time for a given ...
https://dev.mysql.com/doc/refman/8.4/en/invisible-indexes.html
The feature applies to indexes other than primary keys (either explicit or implicit). row *************************** id: 1 select_type: SIMPLE table: t1 partitions: NULL type: range possible_keys: j_idx key: j_idx key_len: 5 ref: NULL rows: 2 ...
https://dev.mysql.com/doc/refman/8.4/en/replication-binlog-encryption.html
To use encryption, a keyring component or plugin must be installed and configured to supply MySQL Server's keyring service. For instructions to do this, see Section 8.4.4, “The MySQL Keyring”. Any supported keyring component or plugin can be ...