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https://dev.mysql.com/doc/refman/8.4/en/performance-schema.html
These tables can be queried using SELECT statements like other tables. The MySQL Performance Schema is a feature for monitoring MySQL Server execution at a low level. The Performance Schema has these characteristics: The Performance Schema provides ...
https://dev.mysql.com/doc/refman/8.4/en/primary-key-optimization.html
The primary key for a table represents the column or set of columns that you use in your most vital queries. Query performance benefits from the NOT NULL optimization, because it cannot include any NULL values. With the InnoDB storage engine, the ...
https://dev.mysql.com/doc/refman/8.4/en/problems-with-alias.html
An alias can be used in a query select list to give a column a different name. This restriction is imposed because when the WHERE clause is evaluated, the column value may not yet have been determined. In the select list of a query, a quoted column ...
https://dev.mysql.com/doc/refman/8.4/en/replication-features-invoked.html
Replication of invoked features such as loadable functions and stored programs (stored procedures and functions, triggers, and events) provides the following characteristics: The effects of the feature are always replicated. The following ...
https://dev.mysql.com/doc/refman/8.4/en/replication-options-binary-log.html
Startup Options Used with Binary Logging System Variables Used with Binary Logging You can use the mysqld options and system variables that are described in this section to affect the operation of the binary log as well as to control which ...
https://dev.mysql.com/doc/refman/8.4/en/replication-options-reference.html
The following two sections provide basic information about the MySQL command-line options and system variables applicable to replication and the binary log. Replication Options and Variables The command-line options and system variables in the ...
https://dev.mysql.com/doc/refman/8.4/en/reset-binary-logs-and-gtids.html
When replication is running correctly, issue STOP REPLICA followed by RESET REPLICA (both on the replica), then verify that no unwanted data from the test queries exists on the replica. Note This statement takes the place of the old RESET MASTER ...
https://dev.mysql.com/doc/refman/8.4/en/row-constructor-optimization.html
For example, these two statements are semantically equivalent: SELECT * FROM t1 WHERE (column1,column2) = (1,1); SELECT * FROM t1 WHERE column1 = 1 AND column2 = 1; In addition, the optimizer handles both expressions the same way. The optimizer is ...
https://dev.mysql.com/doc/refman/8.4/en/secure-client-programming.html
Client applications that access MySQL should use the following guidelines to avoid interpreting external data incorrectly or exposing sensitive information. Handle External Data Properly Handle MySQL Error Messages Properly Handle External Data ...
https://dev.mysql.com/doc/refman/8.4/en/selecting-columns.html
If you do not want to see entire rows from your table, just name the columns in which you are interested, separated by commas.