PDF (US Ltr)
- 43.2Mb
PDF (A4)
- 43.3Mb
Man Pages (TGZ)
- 295.2Kb
Man Pages (Zip)
- 400.4Kb
Info (Gzip)
- 4.3Mb
Info (Zip)
- 4.3Mb
Search Results
https://dev.mysql.com/doc/refman/8.0/en/subquery-materialization.html
The first time MySQL needs the subquery result, it materializes that result into a temporary table. Any subsequent time the result is needed, MySQL refers again to the temporary table. If materialization is not used, the optimizer sometimes rewrites ... The optimizer uses materialization to enable more efficient subquery ...
https://dev.mysql.com/doc/refman/8.0/en/subquery-restrictions.html
In MySQL, it can produce nondeterministic results because f() might be executed a different number of times for different executions of a given query depending on how the optimizer chooses to handle it. FROM t...) AS dt ...); Here the result from ...
https://dev.mysql.com/doc/refman/8.0/en/charset-unicode-utf8.html
utf8mb3 remains supported for the lifetimes of the MySQL 8.0.x and following LTS release series, as well as in MySQL 8.0. utf8 has been used by MySQL in the past as an alias for the utf8mb3 character set, but this usage is now deprecated; in MySQL ...For more information, see Section 12.9.2, “The utf8mb3 Character Set (3-Byte UTF-8 Unicode ...
https://dev.mysql.com/doc/refman/8.0/en/charset-unicode-utf8mb3.html
utf8mb3 remains supported for the lifetimes of the MySQL 8.0.x and following LTS release series, as well as in MySQL 8.0. Expect utf8mb3 to be removed in a future major release of MySQL. Since changing character sets can be a complex and ... The ...
https://dev.mysql.com/doc/refman/8.0/en/index-statistics.html
When a given index value yields a large number of rows, the index is less useful and MySQL is less likely to use it. This affects ref accesses for comparisons of the form tbl_name.key = expr: MySQL does not access the table if the current value of ... Storage engines collect statistics about tables for use by the ...
https://dev.mysql.com/doc/refman/8.0/en/innodb-performance-optimizer-statistics.html
You can query optimizer statistics data in the mysql.innodb_table_stats and mysql.innodb_index_stats tables. You can view the last_update column of the mysql.innodb_table_stats and mysql.innodb_index_stats tables to see when statistics were last ...
https://dev.mysql.com/doc/refman/8.0/en/multiple-server-clients.html
On Unix, set the MYSQL_UNIX_PORT and MYSQL_TCP_PORT environment variables to point to the Unix socket file and TCP/IP port number before you start your clients. If you normally use a specific socket file or port number, you can place commands to set ...Start the client with --protocol=TCP to connect using TCP/IP, --protocol=SOCKET to connect using a Unix socket file, --protocol=PIPE to connect using a named pipe, or --protocol=MEMORY to connect using shared ...
https://dev.mysql.com/doc/refman/8.0/en/nested-join-optimization.html
As a result, the execution time for the query may improve immensely. The following discussion refers to the join syntax described in Section 15.2.13.2, “JOIN Clause”. The syntax of table_factor is extended in comparison with the SQL Standard.
https://dev.mysql.com/doc/refman/8.0/en/programs-development.html
This section describes some utilities that you may find useful when developing MySQL programs. This works well for programs that use the last instance of an option that is specified multiple times. Check the source code of any of the standard MySQL ...In shell scripts, you can use the my_print_defaults program to parse option files and see what options would be used by a given ...
https://dev.mysql.com/doc/refman/8.0/en/recovery-from-backups.html
| mysql For more information about using mysqlbinlog to process binary log files, see Section 9.5, “Point-in-Time (Incremental) Recovery”. The full backup file is just a set of SQL statements, so restoring it is very easy: $> mysql < ... Now, ...