https://dev.mysql.com/connection-compression-control.html
Because enabling compression decreases performance, its benefits occur primarily when there is low network bandwidth, network transfer time dominates the cost of compression and decompression operations, and result sets are large. To configure that ... Connections to the server can use a compressed protocol that reduces the number of bytes sent over the ...
https://dev.mysql.com/connection-control-variables.html
If the CONNECTION_CONTROL plugin is installed, it exposes this status variable: Connection_control_delay_generated The number of times the server added a delay to its response to a failed connection attempt. Assigning a value to ... This section ...
https://dev.mysql.com/constant-folding-optimization.html
Comparisons between constants and column values in which the constant value is out of range or of the wrong type with respect to the column type are now handled once during query optimization rather row-by-row than during execution. The comparisons ...
https://dev.mysql.com/constraint-foreign-key.html
MATCH options do not have any other effect in MySQL, which in effect enforces MATCH SIMPLE semantics full-time. Foreign keys let you cross-reference related data across tables, and foreign key constraints help keep this spread-out data consistent.
https://dev.mysql.com/corrupted-myisam-tables.html
You are using an external program (such as myisamchk) to modify a table that is being modified by the server at the same time. Even though the MyISAM table format is very reliable (all changes to a table made by an SQL statement are written before ...
https://dev.mysql.com/crashing.html
Some external program is manipulating data files or index files at the same time as mysqld without locking the table properly. Each MySQL version is tested on many platforms before it is released. This does not mean that there are no bugs in MySQL, ...
https://dev.mysql.com/create-function-udf.html
All active functions are reloaded each time the server starts, unless you start mysqld with the --skip-grant-tables option. CREATE [AGGREGATE] FUNCTION function_name RETURNS {STRING|INTEGER|REAL|DECIMAL} SONAME shared_library_name A user-defined ...
https://dev.mysql.com/create-index.html
CREATE [UNIQUE | FULLTEXT | SPATIAL] INDEX index_name [index_type] ON tbl_name (key_part,...) [index_option] [algorithm_option | lock_option] ... This guideline is especially important for InnoDB tables, where the primary key determines the ...
https://dev.mysql.com/create-logfile-group.html
There can be only one log file group per NDB Cluster instance at any given time. CREATE LOGFILE GROUP logfile_group ADD UNDOFILE 'undo_file' [INITIAL_SIZE [=] initial_size] [UNDO_BUFFER_SIZE [=] undo_buffer_size] [REDO_BUFFER_SIZE [=] ...
https://dev.mysql.com/create-table-check-constraints.html
Note Constraint expression evaluation uses the SQL mode in effect at evaluation time. Prior to MySQL 8.0.16, CREATE TABLE permits only the following limited version of table CHECK constraint syntax, which is parsed and ignored: CHECK (expr) As of ...
