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https://dev.mysql.com/doc/refman/8.4/en/mysql-cluster-options-variables.html
Two additional sources of information about pushed join performance are available: The status variables Ndb_pushed_queries_defined, Ndb_pushed_queries_dropped, Ndb_pushed_queries_executed, and Ndb_pushed_reads. Setting ndb_row_checksum to 0 means ...
https://dev.mysql.com/doc/refman/8.4/en/mysql-cluster-replication-failover.html
In the event that the primary Cluster replication process fails, it is possible to switch over to the secondary replication channel. This means that the ndb_apply_status table contains information for the replica on this host as well as for any ...
https://dev.mysql.com/doc/refman/8.4/en/mysql-indexes.html
Indexes are used to find rows with specific column values quickly. Without an index, MySQL must begin with the first row and then read through the entire table to find the relevant rows. If the table has an index for the columns in question, MySQL ...
https://dev.mysql.com/doc/refman/8.4/en/no-matching-rows.html
If you have a complicated query that uses many tables but that returns no rows, you should use the following procedure to find out what is wrong: Test the query with EXPLAIN to check whether you can find something that is obviously wrong. Select ...
https://dev.mysql.com/doc/refman/8.4/en/partitioning-limitations-partitioning-keys-unique-keys.html
This section discusses the relationship of partitioning keys with primary keys and unique keys. The rule governing this relationship can be expressed as follows: All columns used in the partitioning expression for a partitioned table must be part ...
https://dev.mysql.com/doc/refman/8.4/en/privileges-provided.html
AUDIT_ABORT_EXEMPT Allows queries blocked by an “abort” item in the audit log filter. SKIP_QUERY_REWRITE Queries issued by a user with this privilege are not subject to being rewritten by the Rewriter plugin (see Section 7.6.4, “The Rewriter ... The privileges granted to a MySQL account determine which operations the account can ...
https://dev.mysql.com/doc/refman/8.4/en/replication-options-source.html
This section describes the server options and system variables that you can use on replication source servers. You can specify the options either on the command line or in an option file. On the source and each replica, you must set the server_id ...
https://dev.mysql.com/doc/refman/8.4/en/spatial-relation-functions-mbr.html
MySQL provides several MySQL-specific functions that test the relationship between minimum bounding rectangles (MBRs) of two geometries g1 and g2. The return values 1 and 0 indicate true and false, respectively. The MBR (also known as the bounding ...
https://dev.mysql.com/doc/refman/8.4/en/stored-objects-security.html
If the account you are searching for does not exist, any objects displayed by those queries are orphan objects. Stored programs (procedures, functions, triggers, and events) and views are defined prior to use and, when referenced, execute within a ...
https://dev.mysql.com/doc/refman/8.4/en/where-optimization.html
You might be tempted to rewrite your queries to make arithmetic operations faster, while sacrificing readability. Each table index is queried, and the best index is used unless the optimizer believes that it is more efficient to use a table scan.