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https://dev.mysql.com/doc/refman/8.4/en/innodb-deadlock-example.html
Client A enables innodb_print_all_deadlocks, creates two tables, 'Animals' and 'Birds', and inserts data into each. The following example illustrates how an error can occur when a lock request causes a deadlock. Thererfore, the previous read-only ...
https://dev.mysql.com/doc/refman/8.4/en/innodb-locking.html
For such cases, InnoDB creates a hidden clustered index and uses this index for record locking. Client A creates a table containing two index records (90 and 102) and then starts a transaction that places an exclusive lock on index records with an ...Shared and Exclusive Locks Intention Locks Record Locks Gap Locks Next-Key Locks Insert Intention Locks AUTO-INC Locks Predicate Locks for Spatial Indexes Shared and Exclusive Locks InnoDB implements standard row-level locking where there are two types of locks, shared (S) locks and exclusive (X) ...
https://dev.mysql.com/doc/refman/8.4/en/innodb-migration.html
To move databases in a binary format from Unix to Windows or from Windows to Unix, create all databases and tables using lowercase names. In addition, MySQL Enterprise Backup can create compressed backup files, and back up subsets of tables. This ...
https://dev.mysql.com/doc/refman/8.4/en/innodb-moving-data-files-offline.html
Add the directories of file-per-table and general tablespaces created with an absolute path or in a location outside of the data directory to the innodb_directories setting. The innodb_directories variable, which defines directories to scan at ...
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 ...