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https://dev.mysql.com/doc/refman/8.4/en/disk-issues.html
For information about optimizing an InnoDB configuration to improve I/O performance, see Section 10.5.8, “Optimizing InnoDB Disk I/O”. You have to choose to optimize for random or sequential access. This section describes ways to configure ...
https://dev.mysql.com/doc/internals/en/optimizer-or-relations.html
An ORed search has the form condition1 OR condition2, as in this example: WHERE column1 = 'x' OR column2 = 'y' Here the optimizer's decision is to use a sequential scan. See Section 7.2.2.5.2, “Index Merge Optimizer” and Index Merge ...There is ...
https://dev.mysql.com/doc/internals/en/optimizer-partition-pruning.html
Therefore its implementation is a part of the MySQL Query Optimizer. The extraction process uses the Range Analyzer — a part of the MySQL optimizer that produces plans for the range access method. Note In certain cases the result of the RANGE ...
https://dev.mysql.com/doc/refman/8.4/en/hash-joins.html
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 variable. This means ...row *************************** id: 1 select_type: SIMPLE table: t1 partitions: NULL type: ALL possible_keys: NULL key: NULL key_len: NULL ref: NULL rows: 1 filtered: 100.00 Extra: NULL ...
https://dev.mysql.com/doc/refman/8.4/en/information-schema-optimizer-trace-table.html
The OPTIMIZER_TRACE table provides information produced by the optimizer tracing capability for traced statements. The OPTIMIZER_TRACE table has these columns: QUERY The text of the traced statement. MISSING_BYTES_BEYOND_MAX_MEM_SIZE Each ...If ...
https://dev.mysql.com/doc/refman/8.4/en/optimizing-myisam-bulk-data-loading.html
These performance tips supplement the general guidelines for fast inserts in Section 10.2.5.1, “Optimizing INSERT Statements”. LOAD DATA performs the preceding optimization automatically if the MyISAM table into which you insert data is empty.
https://dev.mysql.com/doc/mysql-enterprise-backup/8.4/en/backup-performance.html
When optimizing and tuning the backup procedure, measure both the raw performance (how long it takes the backup to complete) and the amount of overhead on the database server. See Section 13.2, “Optimizing Restore Performance” for performance ...
https://dev.mysql.com/doc/internals/en/optimizer-constants-constant-tables.html
The optimizer does some of the transformation because of constant propagation, which we described earlier. A MySQL constant is something more than a mere literal in the query. unique_not_null_column INT NOT NULL UNIQUE then this expression FROM ...
https://dev.mysql.com/doc/internals/en/optimizer-index-join-type.html
Consider this query: SELECT column1 FROM Table1; If column1 is indexed, then the optimizer may choose to retrieve the values from the index rather than from the table. For this query: SELECT column1, column2 FROM Table1; the optimizer will use join ...An index which is used this way is called a covering index in most ...
https://dev.mysql.com/doc/refman/8.4/en/optimizing-innodb-bulk-data-loading.html
These performance tips supplement the general guidelines for fast inserts in Section 10.2.5.1, “Optimizing INSERT Statements”. For optimal performance when loading data into an InnoDB FULLTEXT index, follow this set of steps: Define a column ...