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https://dev.mysql.com/roles.html
To specify mandatory roles at server startup, define mandatory_roles in your server my.cnf file: [mysqld] mandatory_roles='role1,role2@localhost,r3@%.example.com' To set and persist mandatory_roles at runtime, use a statement like this: SET PERSIST ...Like user accounts, roles can have privileges granted to and revoked from ...
https://dev.mysql.com/routines-table.html
DATETIME_PRECISION For stored function temporal return values, the fractional seconds precision. LAST_ALTERED The date and time when the routine was last modified. The ROUTINES table provides information about stored routines (stored procedures and ...
https://dev.mysql.com/semijoins.html
A semijoin is a preparation-time transformation that enables multiple execution strategies such as table pullout, duplicate weedout, first match, loose scan, and materialization. For an inner join between two tables, the join returns a row from one ...The optimizer uses semijoin strategies to improve subquery execution, as described in this ...
https://dev.mysql.com/set.html
It also does not matter how many times a given element is listed in the value. When the value is retrieved later, each element in the value appears once, with elements listed according to the order in which they were specified at table creation time. A SET is a string object that can have zero or more values, each of which must be chosen from a list of permitted values specified when the table is ...
https://dev.mysql.com/setting-environment-variables.html
To have the settings take effect each time you log in, use the interface provided by your system or place the appropriate command or commands in a startup file that your command interpreter reads each time it starts. Environment variables can be ...
https://dev.mysql.com/show-profile.html
Note The SHOW PROFILE and SHOW PROFILES statements are deprecated and will be removed in a future MySQL release. Use the Performance Schema instead; see Section 26.19.1, “Query Profiling Using Performance Schema”. To control profiling, use the ...
https://dev.mysql.com/sorted-index-builds.html
InnoDB performs a bulk load instead of inserting one index record at a time when creating or rebuilding indexes. Prior to the introduction of sorted index builds, index entries were inserted into the B-tree one record at a time using insert APIs.
https://dev.mysql.com/sql-prepared-statements.html
Using prepared statements with placeholders for parameter values has the following benefits: Less overhead for parsing the statement each time it is executed. The statement for a cursor is checked at cursor creation time, so the statement cannot be ...Typically, database applications process large volumes of almost-identical statements, with only changes to literal or variable values in clauses such as WHERE for queries and deletes, SET for updates, and VALUES for ...
https://dev.mysql.com/statistics-table.html
The information_schema_stats_expiry system variable defines the period of time before cached table statistics expire. To update cached values at any time for a given table, use ANALYZE TABLE. If there are no cached statistics or statistics have ...
https://dev.mysql.com/stored-objects-security.html
Creating a stored object with a nonexistent DEFINER account may have negative consequences: For a stored routine, an error occurs at routine execution time if the SQL SECURITY value is DEFINER but the definer account does not exist. For an event, an ... Stored programs (procedures, functions, triggers, and events) and views are defined prior to use and, when referenced, execute within a security context that determines their ...
Document created the 26/06/2006, last modified the 26/10/2018
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