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https://dev.mysql.com/doc/refman/8.4/en/data-masking-component-functions.html
The string must be a suitable length for the Primary Account Number, but is not otherwise checked. Warning Values returned from gen_rnd_canada_sin() should be used only for test purposes, and are not suitable for publication. Warning Values returned ...mask_canada_sin(str [, mask_char]) Masks a Canada Social Insurance Number (SIN) and returns the number with all meaningful digits replaced by 'X' ...
https://dev.mysql.com/doc/refman/8.4/en/data-masking-plugin-usage.html
Suppose that a customer table containing customer records has these columns: id: Customer ID number. Creating Views that Display Masked Data If masked data from a table is used for multiple queries, it may be convenient to define a view that ...
https://dev.mysql.com/doc/refman/8.4/en/delete-optimization.html
The time required to delete individual rows in a MyISAM table is exactly proportional to the number of indexes. To delete all rows from a MyISAM table, TRUNCATE TABLE tbl_name is faster than DELETE FROM tbl_name. Truncate operations are not ...To ...
https://dev.mysql.com/doc/refman/8.4/en/drop-database.html
DROP {DATABASE | SCHEMA} [IF EXISTS] db_name DROP DATABASE drops all tables in the database and deletes the database. Dropping a database does not remove any TEMPORARY tables that were created in that database. TEMPORARY tables are automatically ...
https://dev.mysql.com/doc/refman/8.4/en/encryption-functions.html
One way to make collisions detectable is to make the hash column a primary key. Both HKDF and PBKDF2 can use salts, and their use is recommended to help prevent attacks based on dictionaries of common passwords or rainbow tables. The password is ...
https://dev.mysql.com/doc/refman/8.4/en/estimating-performance.html
For small tables, you can usually find a row in one disk seek (because the index is probably cached). For bigger tables, you can estimate that, using B-tree indexes, you need this many seeks to find a row: log(row_count) / log(index_block_length / 3 ... In most cases, you can estimate query performance by counting disk ...
https://dev.mysql.com/doc/refman/8.4/en/events-configuration.html
Starting the MySQL server with the --skip-grant-tables option causes event_scheduler to be set to DISABLED, overriding any other value set either on the command line or in the my.cnf or my.ini file (Bug #26807). This table can be queried to obtain ... Events are executed by a special event scheduler thread; when we refer to the Event Scheduler, we actually refer to this ...
https://dev.mysql.com/doc/refman/8.4/en/events-metadata.html
To obtain metadata about events: Query the EVENTS table of the INFORMATION_SCHEMA database. Event times can be obtained by selecting from the Information Schema EVENTS table or from SHOW EVENTS, but they are reported as ETZ or STZ values. Value ...
https://dev.mysql.com/doc/refman/8.4/en/faqs-general.html
For the syntax required to perform multiple-table updates, see Section 15.2.17, “UPDATE Statement”; for that required to perform multiple-table deletes, see Section 15.2.2, “DELETE Statement”. A multiple-table insert can be accomplished ...
https://dev.mysql.com/doc/refman/8.4/en/flow-control-functions.html
The default return type of IF() (which may matter when it is stored into a temporary table) is calculated as follows: If expr2 or expr3 produce a string, the result is a string. The second syntax returns the result for the first condition that is ...