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https://dev.mysql.com/doc/relnotes/mysql/8.4/en/news-8-4-0.html
(WL #16017) Optimizer Notes This release adds support for automatic updates of histograms. (Bug #36053241, WL #15786) The multi-range read (MRR) optimization did not perform as well as in previous releases. (WL #16044) Important Change: This release ...(Bug #36301441) Audit log filtering by type, using error as the type, did not work ...
https://dev.mysql.com/doc/refman/8.4/en/descending-indexes.html
Descending indexes also make it possible for the optimizer to use multiple-column indexes when the most efficient scan order mixes ascending order for some columns and descending order for others. Indexes that have descending key parts are not used ... MySQL supports descending indexes: DESC in an index definition is no longer ignored but causes storage of key values in descending ...
https://dev.mysql.com/doc/refman/8.4/en/index-statistics.html
Storage engines collect statistics about tables for use by the optimizer. For optimizer purposes, an important statistic is the average value group size. For optimization purposes, the relevant value is the average size of the non-NULL value groups. This makes index appear to the optimizer to be less useful than it really is for joins that look for non-NULL ...
https://dev.mysql.com/doc/refman/8.4/en/json.html
The MySQL optimizer also looks for compatible indexes on virtual columns that match JSON expressions. Partial Updates of JSON Values In MySQL 8.4, the optimizer can perform a partial, in-place update of a JSON column instead of removing the old ...
https://dev.mysql.com/doc/refman/8.4/en/select.html
tbl_name [[AS] alias] [index_hint] The use of index hints provides the optimizer with information about how to choose indexes during query processing. (If no GROUP BY is present, all rows implicitly form a single aggregate group.) The HAVING clause ... SELECT [ALL | DISTINCT | DISTINCTROW ] [HIGH_PRIORITY] [STRAIGHT_JOIN] [SQL_SMALL_RESULT] [SQL_BIG_RESULT] [SQL_BUFFER_RESULT] [SQL_NO_CACHE] [SQL_CALC_FOUND_ROWS] select_expr [, select_expr] ...
https://dev.mysql.com/doc/mysql-enterprise-backup/8.4/en/backup-capacity-options.html
See Section 13.1, “Optimizing Backup Performance” and Section 13.2, “Optimizing Restore Performance” for additional advice about recommended combinations of values for this and other performance-related options for various hardware ... These ...
https://dev.mysql.com/doc/mysql-monitor/8.0/en/performance-advisors-ref.html
For optimal performance, transactions that move through the binary log should be contained within the binary log cache. Default frequency 00:05:00 Default auto-close enabled no InnoDB Buffer Pool Writes May Be Performance Bottleneck For optimal ...
https://dev.mysql.com/doc/relnotes/heatwave/en/news-8-0-30.html
Advisor HeatWave AutoML Functionality Added or Changed Advisor HeatWave Advisor Auto Encoding, which recommends string column encodings, now provides encoding recommendations that optimize query performance. Previously, string column encoding ...
https://dev.mysql.com/doc/refman/8.4/en/analyze-table.html
You can make the statistics collected by ANALYZE TABLE more precise and more stable by enabling innodb_stats_persistent, as explained in Section 17.8.10.1, “Configuring Persistent Optimizer Statistics Parameters”. For more information about key ...ANALYZE [NO_WRITE_TO_BINLOG | LOCAL] TABLE tbl_name UPDATE HISTOGRAM ON col_name [, col_name] ...
https://dev.mysql.com/doc/refman/8.4/en/column-indexes.html
Optimizations are applied to certain kinds of FULLTEXT queries against single InnoDB tables. For this optimization to apply, there must be no WHERE clauses and only a single ORDER BY clause in descending order. For queries that contain full-text ...