https://dev.mysql.com/update.html
Each matching row is updated once, even if it matches the conditions multiple times. The implicit default value is 0 for numeric types, the empty string ('') for string types, and the “zero” value for date and time types. UPDATE is a DML ...
https://dev.mysql.com/using-date.html
MySQL also permits a “relaxed” string format when updating and in a WHERE clause that compares a date to a DATE, DATETIME, or TIMESTAMP column. When you compare a DATE, TIME, DATETIME, or TIMESTAMP to a constant string with the <, <=, =, >=, >, ...You should use this format in UPDATE expressions and in the WHERE clause of SELECT ...
https://dev.mysql.com/using-gdb-on-mysqld.html
In this case, you can only have one thread active at a time. It is very hard to debug MySQL under gdb if you do a lot of new connections the whole time as gdb does not free the memory for old threads. On most systems you can also start mysqld from ...
https://dev.mysql.com/using-log-files.html
You can also try the command EXPLAIN on all SELECT statements that takes a long time to ensure that mysqld is using indexes properly. You can find the queries that take a long time to execute by starting mysqld with the slow query log enabled. Note ...
https://dev.mysql.com/using-systemd.html
For example: [Service] LimitNOFILE=max_open_files Nice=nice_level LimitCore=core_file_limit Environment="LD_PRELOAD=/path/to/malloc/library" Environment="TZ=time_zone_setting" The discussion here uses override.conf as the name of this file. TZ: Set ...If you install MySQL from a source distribution on a platform that uses systemd, obtain systemd support for MySQL by configuring the distribution using the -DWITH_SYSTEMD=1 CMake ...
https://dev.mysql.com/validate-password-installation.html
Note If you install MySQL 8.0 using the MySQL Yum repository, MySQL SLES Repository, or RPM packages provided by Oracle, the validate_password component is enabled by default after you start your MySQL Server for the first time. To install the ...
https://dev.mysql.com/variables-info-table.html
SET_TIME The time at which the variable was most recently set. The default is the time at which the server initialized global system variables during startup. If a variable with a VARIABLE_SOURCE value other than DYNAMIC is set at runtime, ... The ...
https://dev.mysql.com/version-tokens-usage.html
Assignment of a server within a certain group can change at any time. The next time the client sends a statement to server 2, its own token list no longer matches the server token list and an error occurs: mysql> UPDATE emp.employee SET salary = ...
https://dev.mysql.com/what-is-crashing.html
If you have examined all other possibilities and concluded that the MySQL server or a MySQL client is causing the problem, it is time to create a bug report, see Section 1.7, “How to Report Bugs or Problems”. If a program fails, it is always ...
https://dev.mysql.com/windows-create-option-file.html
For options that are used every time the server starts, you may find it most convenient to use an option file to specify your MySQL configuration. Use a --datadir option to specify the new data directory location each time you start the server. If ...
