Search Results
https://dev.mysql.com/doc/refman/8.4/en/fulltext-restrictions.html
Full-text searches are supported for InnoDB and MyISAM tables only. A character-based ngram full-text parser that supports Chinese, Japanese, and Korean (CJK), and a word-based MeCab parser plugin that supports Japanese are provided for use with ...
https://dev.mysql.com/doc/refman/8.4/en/myisam-key-cache.html
It employs a cache mechanism to keep the most frequently accessed table blocks in memory: For index blocks, a special structure called the key cache (or key buffer) is maintained. You can set up multiple key caches and assign table indexes to ... To ...
https://dev.mysql.com/doc/refman/8.4/en/mysql-cluster-disk-data-storage-requirements.html
The following items apply to Disk Data storage requirements: Variable-length columns of Disk Data tables take up a fixed amount of space. You can obtain an estimate the amount of space available in data files and undo log files by querying the ...
https://dev.mysql.com/doc/refman/8.4/en/mysql-cluster-sql-statements.html
SHOW ENGINE NDB STATUS, SHOW ENGINE NDBCLUSTER STATUS The output of this statement contains information about the server's connection to the cluster, creation and usage of NDB Cluster objects, and binary logging for NDB Cluster replication. However, ... This section discusses several SQL statements that can prove useful in managing and monitoring a MySQL server that is connected to an NDB Cluster, and in some cases provide information about the cluster ...
https://dev.mysql.com/doc/refman/8.4/en/outer-join-simplification.html
Table expressions in the FROM clause of a query are simplified in many cases. When the optimizer evaluates plans for outer join operations, it takes into consideration only plans where, for each such operation, the outer tables are accessed before ...At the parser stage, queries with right outer join operations are converted to equivalent queries containing only left join ...
https://dev.mysql.com/doc/refman/8.4/en/performance-schema-atom-molecule-events.html
For a table I/O event, there are usually two rows in events_waits_current, not one. For example, a row fetch might result in rows like this: Row# EVENT_NAME TIMER_START TIMER_END ---- ---------- ----------- --------- 1 wait/io/file/myisam/dfile ...
https://dev.mysql.com/doc/refman/8.4/en/performance-schema-query-profiling.html
The setup_actors table can be used to limit the collection of historical events by host, user, or account to reduce runtime overhead and the amount of data collected in history tables. For example: mysql> SELECT * FROM employees.employees WHERE ...
https://dev.mysql.com/doc/refman/8.4/en/performance-schema-runtime-configuration.html
If you have the UPDATE privilege, you can change Performance Schema operation by modifying setup tables to affect how monitoring occurs. For additional details about these tables, see Section 29.12.2, “Performance Schema Setup Tables”. The ...
https://dev.mysql.com/doc/refman/8.4/en/replication-multi-source-monitoring.html
To monitor the status of replication channels the following options exist: Using the replication Performance Schema tables. The information that was available through these variables has been migrated to the replication performance tables. This ...
https://dev.mysql.com/doc/refman/8.4/en/sys-schema-progress-reporting.html
The following sys schema views provide progress reporting for long-running transactions: processlist session x$processlist x$session Assuming that the required instruments and consumers are enabled, the progress column of these views shows the ...