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https://dev.mysql.com/doc/refman/8.4/en/insert-optimization.html
To optimize insert speed, combine many small operations into a single large operation. Ideally, you make a single connection, send the data for many new rows at once, and delay all index updates and consistency checking until the very end. The size ...
https://dev.mysql.com/doc/refman/8.4/en/join.html
Such subqueries must include an alias to give the subquery result a table name, and may optionally include a list of table column names in parentheses. mysql> SELECT * FROM t1 NATURAL RIGHT JOIN t2; +------+------+------+ | a | c | b | ... MySQL ...
https://dev.mysql.com/doc/refman/8.4/en/keywords.html
Certain keywords, such as SELECT, DELETE, or BIGINT, are reserved and require special treatment for use as identifiers such as table and column names. This may also be true for the names of built-in functions. Some keywords which are otherwise ...
https://dev.mysql.com/doc/refman/8.4/en/kill.html
KILL [CONNECTION | QUERY] processlist_id Each connection to mysqld runs in a separate thread. Thread processlist identifiers can be determined from the ID column of the INFORMATION_SCHEMA PROCESSLIST table, the Id column of SHOW PROCESSLIST output, ...
https://dev.mysql.com/doc/refman/8.4/en/mrr-optimization.html
Reading rows using a range scan on a secondary index can result in many random disk accesses to the base table when the table is large and not stored in the storage engine's cache. With the Disk-Sweep Multi-Range Read (MRR) optimization, MySQL ...
https://dev.mysql.com/doc/refman/8.4/en/multiple-key-caches.html
Where there are multiple key caches, the server must know which cache to use when processing queries for a given MyISAM table. Performance gains occur for other reasons as well: The hot cache is used only for retrieval queries, so its contents are ... Note As of MySQL 8.4, the compound-part structured-variable syntax discussed here for referring to multiple MyISAM key caches is ...
https://dev.mysql.com/doc/refman/8.4/en/mysql-cluster-limitations-syntax.html
Using nullable columns in unique keys and primary keys means that queries using these columns are handled as full table scans. Some SQL statements relating to certain MySQL features produce errors when used with NDB tables, as described in the ...
https://dev.mysql.com/doc/refman/8.4/en/mysql-cluster-ndb-api-statistics.html
A number of types of statistical counters relating to actions performed by or affecting Ndb objects are available. Such actions include starting and closing (or aborting) transactions; primary key and unique key operations; table, range, and pruned ...
https://dev.mysql.com/doc/refman/8.4/en/mysql-cluster-ndbinfo-diskpagebuffer.html
The diskpagebuffer table provides statistics about disk page buffer usage by NDB Cluster Disk Data tables. The diskpagebuffer table contains the following columns: node_id The data node ID block_instance Block instance pages_written Number of pages ...
https://dev.mysql.com/doc/refman/8.4/en/mysql-cluster-option-tables.html
Ndb_pushed_queries_defined: Number of joins that API nodes have attempted to push down to data nodes. Ndb_pushed_queries_dropped: Number of joins that API nodes have tried to push down, but failed. Ndb_pushed_queries_executed: Number of joins ...