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https://dev.mysql.com/doc/refman/8.4/en/generated-column-index-optimizations.html
The column is also indexed and the optimizer can take that index into account during execution plan construction. row *************************** id: 1 select_type: SIMPLE table: t1 partitions: NULL type: range possible_keys: gc key: gc key_len: 5 ...For example: CREATE TABLE t1 (f1 INT, gc INT AS (f1 + 1) STORED, INDEX (gc)); The generated column, gc, is defined as the expression f1 + ...
https://dev.mysql.com/doc/refman/8.4/en/select-optimization.html
NDB Cluster supports a join pushdown optimization whereby a qualifying join is sent in its entirety to NDB Cluster data nodes, where it can be distributed among them and executed in parallel. For more information about this optimization, see ...
https://dev.mysql.com/doc/refman/8.4/en/where-optimization.html
This section discusses optimizations that can be made for processing WHERE clauses. The examples use SELECT statements, but the same optimizations apply for WHERE clauses in DELETE and UPDATE statements. Note Because work on the MySQL optimizer is ...You might be tempted to rewrite your queries to make arithmetic operations faster, while sacrificing ...
https://dev.mysql.com/doc/refman/8.4/en/derived-condition-pushdown-optimization.html
If this optimization is disabled by optimizer_switch, you can enable it for a specific query using the DERIVED_CONDITION_PUSHDOWN optimizer hint. To disable the optimization for a given query, use the NO_DERIVED_CONDITION_PUSHDOWN optimizer hint.
https://dev.mysql.com/doc/refman/8.4/en/index-merge-optimization.html
The optimizer chooses between different possible Index Merge algorithms and other access methods based on cost estimates of the various available options. Influencing Index Merge Optimization Use of Index Merge is subject to the value of the ... The ...
https://dev.mysql.com/doc/refman/8.4/en/optimizer-statistics.html
The column_statistics data dictionary table stores histogram statistics about column values, for use by the optimizer in constructing query execution plans. The optimizer applies histogram statistics to determine row estimates based on the ...The ...
https://dev.mysql.com/doc/refman/8.4/en/outer-join-optimization.html
(In other words, any condition in the WHERE clause is not used.) All standard join optimizations are performed, with the exception that a table is always read after all tables on which it depends. To provide a hint about the table join order, use ...
https://dev.mysql.com/doc/internals/en/optimizer-code.html
This diagram shows the structure of the function handle_select() in /sql/sql_select.cc (the server code that handles a query): handle_select() mysql_select() JOIN::prepare() setup_fields() JOIN::optimize() /* optimizer is from here ... */ ...to ...
https://dev.mysql.com/doc/refman/8.4/en/innodb-performance-optimizer-statistics.html
This section describes how to configure persistent and non-persistent optimizer statistics for InnoDB tables. Persistent optimizer statistics are persisted across server restarts, allowing for greater plan stability and more consistent query ...You ...
https://dev.mysql.com/doc/refman/8.4/en/is-null-optimization.html
MySQL can perform the same optimization on col_name IS NULL that it can use for col_name = constant_value. This optimization does not occur in cases when the column might produce NULL anyway (for example, if it comes from a table on the right side ...For example, MySQL can use indexes and ranges to search for NULL with IS ...