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https://dev.mysql.com/doc/refman/8.4/en/innodb-online-ddl-limitations.html
The following limitations apply to online DDL operations: The table is copied when creating an index on a TEMPORARY TABLE. Secondary indexes are not created as efficiently because keys are inserted in the order they appeared in the primary key. The ...
https://dev.mysql.com/doc/refman/8.4/en/innodb-online-ddl-space-requirements.html
Temporary log files: A temporary log file records concurrent DML when an online DDL operation creates an index or alters a table. Temporary sort files: Online DDL operations that rebuild the table write temporary sort files to the MySQL temporary ...
https://dev.mysql.com/doc/refman/8.4/en/json-table-functions.html
This is equivalent to specifying a column as AUTO_INCREMENT in a CREATE TABLE statement, and can be used to distinguish parent rows with the same value for multiple rows generated by a NESTED [PATH] clause. This section contains information about ...
https://dev.mysql.com/doc/refman/8.4/en/limit-optimization.html
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 data. MySQL sometimes optimizes a query that has a LIMIT row_count clause and no ...
https://dev.mysql.com/doc/refman/8.4/en/local-variable-scope.html
Because local variables are in scope only during stored program execution, references to them are not permitted in prepared statements created within a stored program. The scope of a local variable is the BEGIN ... The variable can be referred to ...
https://dev.mysql.com/doc/refman/8.4/en/multiple-column-indexes.html
MySQL can create composite indexes (that is, indexes on multiple columns). A multiple-column index can be considered a sorted array, the rows of which contain values that are created by concatenating the values of the indexed columns. For certain ...
https://dev.mysql.com/doc/refman/8.4/en/multiple-tables.html
Given these considerations, the CREATE TABLE statement for the event table might look like this: mysql> CREATE TABLE event (name VARCHAR(20), date DATE, type VARCHAR(15), remark VARCHAR(255)); As with the pet table, it is easiest to load the initial ... The pet table keeps track of which pets you ...
https://dev.mysql.com/doc/refman/8.4/en/myisam-table-formats.html
The third, compressed format, can be created only with the myisampack utility (see Section 6.6.6, “myisampack — Generate Compressed, Read-Only MyISAM Tables”). When you use CREATE TABLE or ALTER TABLE for a table that has no BLOB or TEXT ...
https://dev.mysql.com/doc/refman/8.4/en/mysql-cluster-config-example.html
To create a default value section, simply add the word default to the section name. To configure them all, create an [ndbd default] section that contains a DataMemory line to specify the data memory size. To support NDB Cluster, you should update ...
https://dev.mysql.com/doc/refman/8.4/en/mysql-cluster-limitations-database-objects.html
In addition, the maximum offset for a fixed-width column of an NDB table is 8188 bytes; attempting to create a table that violates this limitation fails with NDB error 851 Maximum offset for fixed-size columns exceeded. Some database objects such ...