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https://dev.mysql.com/doc/refman/8.4/en/create-user.html
CREATE USER permits these resource_option values: MAX_QUERIES_PER_HOUR count, MAX_UPDATES_PER_HOUR count, MAX_CONNECTIONS_PER_HOUR count For all accounts named by the statement, these options restrict how many queries, updates, and connections to ...
https://dev.mysql.com/doc/refman/8.4/en/data-masking-plugin-usage.html
Creating Views that Display Masked Data If masked data from a table is used for multiple queries, it may be convenient to define a view that produces masked data. That way, applications can select from the view without performing masking in ...
https://dev.mysql.com/doc/refman/8.4/en/derived-tables.html
For information about lateral derived tables preceded by the LATERAL keyword, see Section 15.2.15.9, “Lateral Derived Tables”. A derived table is an expression that generates a table within the scope of a query FROM clause. For example, a ...
https://dev.mysql.com/doc/refman/8.4/en/distinct-optimization.html
Thus, for more details on the optimization possibilities for DISTINCT queries, see Section 10.2.1.17, “GROUP BY Optimization”. DISTINCT combined with ORDER BY needs a temporary table in many cases. Because DISTINCT may use GROUP BY, learn how ...
https://dev.mysql.com/doc/refman/8.4/en/faqs-mysql-cluster.html
How do I continue to send queries in the event that one of the SQL nodes fails? A.10.40. However, it also means that queries that could otherwise use range scans must be satisfied by other means, which can result in slower selects. How do I continue ... In the following section, we answer questions that are frequently asked about MySQL NDB Cluster and the NDB storage ...
https://dev.mysql.com/doc/refman/8.4/en/faqs-thread-pool.html
This minimizes the overhead and expense of establishing and tearing down connections as queries are submitted to the MySQL server. By contrast, the Thread Pool operates on the MySQL server side and is designed to manage the execution of inbound ...
https://dev.mysql.com/doc/refman/8.4/en/group-replication-bootstrap.html
The process of starting a group for the first time is called bootstrapping. The bootstrap should only be done by a single server, the one that starts the group and only once. This is why the value of the group_replication_bootstrap_group option was ...
https://dev.mysql.com/doc/refman/8.4/en/hash-joins.html
This means that the types of queries which can be optimized using hash joins include those in the following list (with examples): Inner non-equi-join: mysql> EXPLAIN FORMAT=TREE SELECT * FROM t1 JOIN t2 ON t1.c1 < t2.c1\G *************************** ...It is possible to control whether hash joins are employed using one of the BNL and NO_BNL optimizer hints, or by setting block_nested_loop=on or block_nested_loop=off as part of the setting for the optimizer_switch server system ...
https://dev.mysql.com/doc/refman/8.4/en/index-hints.html
For example, the following two queries are equivalent: SELECT * FROM t1 USE INDEX (i1) IGNORE INDEX (i2) USE INDEX (i2); SELECT * FROM t1 USE INDEX (i1); For FULLTEXT searches, index hints work as follows: For natural language mode searches, index ... Index hints give the optimizer information about how to choose indexes during query ...
https://dev.mysql.com/doc/refman/8.4/en/index-merge-optimization.html
The Index Merge access method retrieves rows with multiple range scans and merges their results into one. This access method merges index scans from a single table only, not scans across multiple tables. The merge can produce unions, intersections, ...