No cache version.
Caching disabled. Default setting for this page:enabled (code DEF204)
If the display is too slow, you can disable the user mode to view the cached version.
Rechercher dans le manuel MySQL
Search Results
https://dev.mysql.com/derived-table-optimization.html
When this happens, query execution is quicker by the time needed to perform materialization. If a CTE is materialized by a query, it is materialized once for the query, even if the query references it several times. This is similar to automatic ...
https://dev.mysql.com/group-replication-responses-failure-expel.html
You can use the group_replication_member_expel_timeout system variable, which is available from MySQL 8.0.13, to allow additional time between the creation of a suspicion and the expulsion of the suspect member. A group member is expelled when ...
https://dev.mysql.com/group-replication-understanding-consistency-guarantees.html
With the first approach, the group takes the minimum time possible to secure a stable group membership after a primary failure by electing a new primary and then allowing data access immediately while it is still applying any possible backlog from ... In terms of distributed consistency guarantees, either in normal or failure repair operations, Group Replication has always been an eventual consistency ...
https://dev.mysql.com/innodb-buffer-pool-stats-table.html
PAGES_MADE_YOUNG_RATE The number of pages made young per second (pages made young since the last printout / time elapsed). PAGES_MADE_NOT_YOUNG_RATE The number of pages not made per second (pages not made young since the last printout / time ... The ...
https://dev.mysql.com/innodb-compression-internals.html
Every time something inside a block is modified, the whole block is recompressed before it is written to disk. It is important to minimize the number of times B-tree nodes are split, as well as to minimize the need to uncompress and recompress their ... This section describes some internal implementation details about compression for InnoDB ...
https://dev.mysql.com/innodb-persistent-stats.html
The persistent optimizer statistics feature improves plan stability by storing statistics to disk and making them persistent across server restarts so that the optimizer is more likely to make consistent choices each time for a given query. You ...
https://dev.mysql.com/internal-locking.html
At times, it may be more efficient to disable deadlock detection and rely on the innodb_lock_wait_timeout setting for transaction rollback when a deadlock occurs. MySQL uses table-level locking for MyISAM, MEMORY, and MERGE tables, permitting only ... This section discusses internal locking; that is, locking performed within the MySQL server itself to manage contention for table contents by multiple ...
https://dev.mysql.com/json.html
BLOB BIT OPAQUE DATETIME TIME DATE BOOLEAN ARRAY OBJECT STRING INTEGER, DOUBLE NULL For JSON values of the same precedence, the comparison rules are type specific: BLOB The first N bytes of the two values are compared, where N is the number of bytes ...The JSON data type provides these advantages over storing JSON-format strings in a string column: Automatic validation of JSON documents stored in JSON ...
https://dev.mysql.com/mysqld-safe.html
mysqld_safe adds some safety features such as restarting the server when an error occurs and logging runtime information to an error log. --mysqld-safe-log-timestamps This option controls the format for timestamps in log output produced by ...
https://dev.mysql.com/nested-loop-joins.html
Nested-Loop Join Algorithm Block Nested-Loop Join Algorithm A simple nested-loop join (NLJ) algorithm reads rows from the first table in a loop one at a time, passing each row to a nested loop that processes the next table in the join. This process ... MySQL executes joins between tables using a nested-loop algorithm or variations on ...
Document created the 26/06/2006, last modified the 26/10/2018
Source of the printed document:https://www.gaudry.be/en/mysql-rf-fct-time-p-13.html
The infobrol is a personal site whose content is my sole responsibility. The text is available under CreativeCommons license (BY-NC-SA). More info on the terms of use and the author.
References
These references and links indicate documents consulted during the writing of this page, or which may provide additional information, but the authors of these sources can not be held responsible for the content of this page.
The author This site is solely responsible for the way in which the various concepts, and the freedoms that are taken with the reference works, are presented here. Remember that you must cross multiple source information to reduce the risk of errors.
