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https://dev.mysql.com/doc/refman/8.4/en/mysqldumpslow.html
The MySQL slow query log contains information about queries that take a long time to execute (see Section 7.4.5, “The Slow Query Log”). mysqldumpslow parses MySQL slow query log files and summarizes their contents. Normally, mysqldumpslow ...
https://dev.mysql.com/doc/refman/8.4/en/network-namespace-support.html
A network namespace is a logical copy of the network stack from the host system. Network namespaces are useful for setting up containers or virtual environments. Each namespace has its own IP addresses, network interfaces, routing tables, and so ...
https://dev.mysql.com/doc/refman/8.4/en/no-matching-rows.html
If you have a complicated query that uses many tables but that returns no rows, you should use the following procedure to find out what is wrong: Test the query with EXPLAIN to check whether you can find something that is obviously wrong. Select ...
https://dev.mysql.com/doc/refman/8.4/en/option-defaults-equals.html
Due to this behavior, problems can occasionally arise when no value is provided for an option that expects one. Consider the following example, where a user connects to a MySQL server running on host tonfisk as user jon: $> mysql --host 85.224.35.45 ...
https://dev.mysql.com/doc/refman/8.4/en/partitioning-limitations-storage-engines.html
In MySQL 8.4, partitioning support is not actually provided by the MySQL Server, but rather by a table storage engine's own or native partitioning handler. In MySQL 8.4, only the InnoDB and NDB storage engines provide native partitioning handlers.
https://dev.mysql.com/doc/refman/8.4/en/partitioning-limitations.html
This section discusses current restrictions and limitations on MySQL partitioning support. The following constructs are not permitted in partitioning expressions: Stored procedures, stored functions, loadable functions, or plugins. For a list of ...
https://dev.mysql.com/doc/refman/8.4/en/performance-schema-examples.html
The Performance Schema is a tool to help a DBA do performance tuning by taking real measurements instead of “wild guesses.” This section demonstrates some ways to use the Performance Schema for this purpose. The discussion here relies on the ...
https://dev.mysql.com/doc/refman/8.4/en/performance-schema-filtering-names.html
Names given for filtering operations can be as specific or general as required. For example, to select all file I/O instruments, it is better to use a pattern that includes the entire instrument name prefix: ... WHERE NAME LIKE 'wait/io/file/%'; A ...
https://dev.mysql.com/doc/refman/8.4/en/performance-schema-obtaining-parent-events.html
Rows of this table have a THREAD_ID column indicating the thread ID of the session that owns the lock, and an EVENT_ID column indicating the Performance Schema event that caused the lock. The relation is based on a nested set data model, so the join ...
https://dev.mysql.com/doc/refman/8.4/en/performance-schema-queries.html
Pre-filtering limits which event information is collected and is independent of any particular user. By contrast, post-filtering is performed by individual users through the use of queries with appropriate WHERE clauses that restrict what event ...