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https://dev.mysql.com/doc/refman/8.4/en/mysql-cluster-overview-requirements.html
NDB Cluster requires communication between data nodes and API nodes (including SQL nodes), as well as between data nodes and other data nodes, to execute queries and updates. Communication latency between these processes can directly affect the ...
https://dev.mysql.com/doc/refman/8.4/en/mysql-logging.html
The mysql client can do these types of logging for statements executed interactively: On Unix, mysql writes the statements to a history file. By default, this file is named .mysql_history in your home directory. To specify a different file, set the ...
https://dev.mysql.com/doc/refman/8.4/en/optimizer-issues.html
MySQL uses a cost-based optimizer to determine the best way to resolve a query. In many cases, MySQL can calculate the best possible query plan, but sometimes MySQL does not have enough information about the data at hand and has to make ...
https://dev.mysql.com/doc/refman/8.4/en/optimizing-memory-tables.html
For best performance with MEMORY tables, examine the kinds of queries against each table, and specify the type to use for each associated index, either a B-tree index or a hash index. B-tree indexes are fast for queries that do greater-than or ...
https://dev.mysql.com/doc/refman/8.4/en/partitioning-management-hash-key.html
Tables which are partitioned by hash or by key are very similar to one another with regard to making changes in a partitioning setup, and both differ in a number of ways from tables which have been partitioned by range or list. For that reason, ...
https://dev.mysql.com/doc/refman/8.4/en/partitioning-range.html
You frequently run queries that depend directly on the column used for partitioning the table. A table that is partitioned by range is partitioned in such a way that each partition contains rows for which the partitioning expression value lies ...
https://dev.mysql.com/doc/refman/8.4/en/performance-schema-events-statements-current-table.html
The table stores one row per thread showing the current status of the thread's most recent monitored statement event, so there is no system variable for configuring the table size. Of the tables that contain statement event rows, ...
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.html
This involves the use of WHERE clauses in queries that select information from Performance Schema tables, to specify which of the available events you want to see. For information about writing queries to retrieve information (post-filtering), see ... Events are processed in a producer/consumer fashion: Instrumented code is the source for events and produces events to be ...
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 ...