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https://dev.mysql.com/doc/refman/8.4/en/sys-innodb-buffer-stats-by-table.html
These views summarize the information in the INFORMATION_SCHEMA INNODB_BUFFER_PAGE table, grouped by schema and table. Warning Querying views that access the INNODB_BUFFER_PAGE table can affect performance. Do not query these views on a production ...
https://dev.mysql.com/doc/refman/8.4/en/thread-pool-elements.html
In older versions of MySQL, the monitoring tables were INFORMATION_SCHEMA tables (see Section 28.5, “INFORMATION_SCHEMA Thread Pool Tables”). The INFORMATION_SCHEMA tables are deprecated; expect them to be removed in a future version of MySQL.
https://dev.mysql.com/doc/refman/8.4/en/type-conversion.html
When an operator is used with operands of different types, type conversion occurs to make the operands compatible. For example, MySQL automatically converts strings to numbers as necessary, and vice versa. mysql> SELECT 1+'1'; -> 2 mysql> SELECT ...
https://dev.mysql.com/doc/refman/8.4/en/using-spatial-indexes.html
The optimizer investigates whether available spatial indexes can be involved in the search for queries that use a function such as MBRContains() or MBRWithin() in the WHERE clause. The following query finds all objects that are in the given ...
https://dev.mysql.com/doc/refman/8.4/en/version-tokens-usage.html
Suppose that a management application communicates with a set of servers that are queried by clients to access employee and product databases (named emp and prod, respectively). Before using Version Tokens, install it according to the instructions ...
https://dev.mysql.com/doc/refman/8.4/en/window-functions-frames.html
The definition of a window used with a window function can include a frame clause. A frame is a subset of the current partition and the frame clause specifies how to define the subset. Frames are determined with respect to the current row, which ...
https://dev.mysql.com/doc/relnotes/mysql/8.4/en/news-8-4-1.html
GROUP BY queries were at least twice as slow with the TempTable engine than the Memory engine. It was removed due to a critical issue that could stop the server from restarting following the creation of a very large number of tables (8001 or more).
https://dev.mysql.com/doc/mysql-enterprise-backup/8.4/en/backup-performance.html
For best backup performance and minimal impact on database processing: Do not run long INSERT, UPDATE, or DELETE queries at the time of the backup run. This section describes the performance considerations for backing up a database with MySQL ...
https://dev.mysql.com/doc/mysql-enterprise-backup/8.4/en/glossary.html
Typically used to service user queries, to minimize the query load on the source server. It typically dedicates most of its resources to write operations, leaving user queries to the replicas. These terms are commonly used in information about the ...
https://dev.mysql.com/doc/mysql-cluster-manager/8.4/en/mcm-attribute-tables-mysqld.html
Ndb_pushed_queries_defined: Number of joins that API nodes have attempted to push down to data nodes. Ndb_pushed_queries_dropped: Number of joins that API nodes have tried to push down, but failed. Ndb_pushed_queries_executed: Number of joins ...