Search Results
https://dev.mysql.com/doc/refman/8.4/en/debugging-server.html
If you are using some functionality that is very new in MySQL, you can try to run mysqld with the --skip-new option (which disables all new, potentially unsafe functionality). If mysqld does not want to start, verify that you have no my.cnf files ...
https://dev.mysql.com/doc/refman/8.4/en/declare-handler.html
statement handler_action: { CONTINUE | EXIT | UNDO } condition_value: { mysql_error_code | SQLSTATE [VALUE] sqlstate_value | condition_name | SQLWARNING | NOT FOUND | SQLEXCEPTION } The DECLARE ... HANDLER statement specifies a handler that deals ...
https://dev.mysql.com/doc/refman/8.4/en/diagnostics-area.html
SQL statements produce diagnostic information that populates the diagnostics area. Standard SQL has a diagnostics area stack, containing a diagnostics area for each nested execution context. Standard SQL also supports GET STACKED DIAGNOSTICS syntax ...
https://dev.mysql.com/doc/refman/8.4/en/error-log-configuration.html
In MySQL 8.4, error logging uses the MySQL component architecture described at Section 7.5, “MySQL Components”. The error log subsystem consists of components that perform log event filtering and writing, as well as a system variable that ...
https://dev.mysql.com/doc/refman/8.4/en/error-log-event-fields.html
Error events intended for the error log contain a set of fields, each of which consists of a key/value pair. An event field may be classified as core, optional, or user-defined: A core field is set up automatically for error events. However, its ...
https://dev.mysql.com/doc/refman/8.4/en/error-lost-connection.html
Sometimes the “during query” form happens when millions of rows are being sent as part of one or more queries. Usually it indicates network connectivity trouble and you should check the condition of your network if this error occurs frequently.
https://dev.mysql.com/doc/refman/8.4/en/explain-for-connection.html
To obtain the execution plan for an explainable statement executing in a named connection, use this statement: EXPLAIN [options] FOR CONNECTION connection_id; EXPLAIN FOR CONNECTION returns the EXPLAIN information that is currently being used to ...
https://dev.mysql.com/doc/refman/8.4/en/extensions-to-ansi.html
This gives better performance for some very specific, but quite normal queries. MySQL Server supports some extensions that you are not likely to find in other SQL DBMSs. Be warned that if you use them, your code is most likely not portable to other ...
https://dev.mysql.com/doc/refman/8.4/en/features.html
Statements and Functions Full operator and function support in the SELECT list and WHERE clause of queries. This section describes some of the important characteristics of the MySQL Database Software. In most respects, the roadmap applies to all ...
https://dev.mysql.com/doc/refman/8.4/en/federated-usagenotes.html
Queries that fail to use indexes can thus cause poor performance and network overload. The following items indicate features that the FEDERATED storage engine does and does not support: The remote server must be a MySQL server. The remote table that ...