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https://dev.mysql.com/doc/refman/8.4/en/locking-issues.html
MySQL manages contention for table contents using locking: Internal locking is performed within the MySQL server itself to manage contention for table contents by multiple threads. This type of locking is internal because it is performed entirely ...
https://dev.mysql.com/doc/refman/8.4/en/optimize-benchmarking.html
To measure performance, consider the following factors: Whether you are measuring the speed of a single operation on a quiet system, or how a set of operations (a “workload”) works over a period of time. With simple tests, you usually test how ...
https://dev.mysql.com/doc/refman/8.4/en/optimizer-trace-system-variable.html
The optimizer_trace system variable has these on/off switches: enabled: Enables (ON) or disables (OFF) tracing one_line: If set to ON, the trace contains no whitespace, thus conserving space. This renders the trace difficult to read for humans, ...
https://dev.mysql.com/doc/mysql-enterprise-backup/8.4/en/restore-performance.html
This section describes the performance considerations for restoring a database server with MySQL Enterprise Backup. This subject is important because: The restore operation is the phase of the backup-restore cycle that tends to vary substantially ...
https://dev.mysql.com/doc/mysql-ai/9.5/en/mys-mysqlai-ml-metrics.html
The ML_TRAIN routine includes the optimization_metric option, and the ML_SCORE routine includes the metric option. Both of these options define a metric that must be compatible with the task type and the target data. precision_k: An Oracle ...
https://dev.mysql.com/doc/refman/8.4/en/controlling-query-plan-evaluation.html
The task of the query optimizer is to find an optimal plan for executing an SQL query. Because the difference in performance between “good” and “bad” plans can be orders of magnitude (that is, seconds versus hours or even days), most query ...For small numbers of tables (typically less than 7 to 10) this is not a ...
https://dev.mysql.com/doc/refman/8.4/en/source-configuration-options.html
-DCMAKE_BUILD_TYPE=type The type of build to produce: RelWithDebInfo: Enable optimizations and generate debugging information. Release: Enable optimizations but omit debugging information to reduce the build size. -DWITH_LTO=bool Whether to enable ... The CMake program provides a great deal of control over how you configure a MySQL source ...
https://dev.mysql.com/doc/refman/8.4/en/innodb-information-schema-fulltext_index-tables.html
INNODB_FT_BEING_DELETED: Provides a snapshot of the INNODB_FT_DELETED table; it is used only during an OPTIMIZE TABLE maintenance operation. When OPTIMIZE TABLE is run, the INNODB_FT_BEING_DELETED table is emptied, and DOC_ID values are removed from ...Because the contents of INNODB_FT_BEING_DELETED typically have a short lifetime, this table has limited utility for monitoring or ...
https://dev.mysql.com/doc/refman/8.4/en/condition-filtering.html
In general, the optimizer attempts to put tables with low prefix counts early in the join order to keep the number of row combinations from increasing rapidly. To the extent that the optimizer can use information about conditions on rows selected ...
https://dev.mysql.com/doc/refman/8.4/en/fulltext-fine-tuning.html
Optimizing InnoDB Full-Text Indexes Running OPTIMIZE TABLE on a table with a full-text index rebuilds the full-text index, removing deleted Document IDs and consolidating multiple entries for the same word, where possible. To optimize a full-text ...