https://dev.mysql.com/problems-with-null.html
When reading data with LOAD DATA, empty or missing columns are updated with ''. If you insert NULL into a TIMESTAMP column, the current date and time is inserted. The concept of the NULL value is a common source of confusion for newcomers to SQL, ...
https://dev.mysql.com/replication-options-master.html
A crash of the master and failover to the slave is lossless because the slave is up to date. This section describes the server options and system variables that you can use on replication master servers. You can specify the options either on the ...
https://dev.mysql.com/replication-semisync.html
A crash of the master and failover to the slave is lossless because the slave is up to date. In addition to the built-in asynchronous replication, MySQL 8.0 supports an interface to semisynchronous replication that is implemented by plugins. This ...
https://dev.mysql.com/replication-solutions-switch.html
If you are not using GTIDs for replication, then the slaves should also be run with --log-slave-updates=OFF (logging slave updates is the default). Each MySQL Slave (Slave 1, Slave 2, and Slave 3) is a slave running with binary logging enabled, and ... You can tell a slave to change to a new master using the CHANGE MASTER TO ...
https://dev.mysql.com/select-optimization.html
Keep table statistics up to date by using the ANALYZE TABLE statement periodically, so the optimizer has the information needed to construct an efficient execution plan. Queries, in the form of SELECT statements, perform all the lookup operations ...
https://dev.mysql.com/selecting-all.html
For example, you may happen to think that the birth date for Bowser doesn't seem quite right. Fix only the erroneous record with an UPDATE statement: mysql> UPDATE pet SET birth = '1989-08-31' WHERE name = 'Bowser'; The UPDATE changes only the ...
https://dev.mysql.com/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.
https://dev.mysql.com/selecting-rows.html
As shown in the preceding section, it is easy to retrieve an entire table. But typically you don't want to see the entire table, particularly when it becomes large. Instead, you're usually more interested in answering a particular question, in ...
https://dev.mysql.com/server-plugins.html
Version Tokens enables creation of and synchronization around server tokens that applications can use to prevent accessing incorrect or out-of-date data. MySQL supports a plugin API that enables creation of server components. Plugins can be loaded ...
https://dev.mysql.com/show-create-trigger.html
row *************************** Trigger: ins_sum sql_mode: ONLY_FULL_GROUP_BY,STRICT_TRANS_TABLES, NO_ZERO_IN_DATE,NO_ZERO_DATE, ERROR_FOR_DIVISION_BY_ZERO, NO_ENGINE_SUBSTITUTION SQL Original Statement: CREATE DEFINER=`me`@`localhost` TRIGGER ...
