https://dev.mysql.com/precision-math-examples.html
The floating-point calculation introduces small errors: +--------+------------------+ | d | f | +--------+------------------+ | 1.0000 | 0.99999999999991 | +--------+------------------+ Example 2. Rounding for exact-value columns (DECIMAL and ...
https://dev.mysql.com/range-optimization.html
The range access method uses a single index to retrieve a subset of table rows that are contained within one or several index value intervals. A range condition on a multiple-part index restricts index rows to lie within one or several key tuple ...
https://dev.mysql.com/replace.html
REPLACE [LOW_PRIORITY | DELAYED] [INTO] tbl_name [PARTITION (partition_name [, partition_name] ...)] [(col_name [, col_name] ...)] {VALUES | VALUE} (value_list) [, (value_list)] ... REPLACE [LOW_PRIORITY | DELAYED] [INTO] tbl_name [PARTITION ...
https://dev.mysql.com/replication-options-master.html
For each server, you should pick a unique positive integer in the range from 1 to 232 − 1, and each ID must be different from every other ID in use by any other replication master or slave. Both variables have global and session values, and each ... This section describes the server options and system variables that you can use on replication master ...
https://dev.mysql.com/replication-solutions-diffengines.html
If you are already running a replication solution and want to convert your existing tables to another engine type, follow these steps: Stop the slave from running replication updates: mysql> STOP SLAVE; This will enable you to change engine types ...
https://dev.mysql.com/server-options.html
For a given buffer, the server might need to allocate internal data structures. --basedir=dir_name, -b dir_name Property Value Command-Line Format --basedir=dir_name System Variable basedir Scope Global Dynamic No SET_VAR Hint Applies No Type ...
https://dev.mysql.com/session-state-tracking.html
(To change sessions in a load-balanced environment, it is necessary to detect whether there is session state to take into consideration when deciding whether a switch can be made.) Another use for the tracker mechanism is to permit applications to ...A client can enable these trackers to receive notification of changes to its session ...
https://dev.mysql.com/set-variable.html
The following procedure uses the increment procedure parameter and counter local variable: CREATE PROCEDURE p(increment INT) BEGIN DECLARE counter INT DEFAULT 0; WHILE counter < 10 DO -- ... SET counter = counter + increment; END WHILE; END; The ...
https://dev.mysql.com/show-columns.html
These two statements are equivalent: SHOW COLUMNS FROM mytable FROM mydb; SHOW COLUMNS FROM mydb.mytable; The optional EXTENDED keyword causes the output to include information about hidden columns that MySQL uses internally and are not accessible ... SHOW [EXTENDED] [FULL] {COLUMNS | FIELDS} {FROM | IN} tbl_name [{FROM | IN} db_name] [LIKE 'pattern' | WHERE expr] SHOW COLUMNS displays information about the columns in a given ...
https://dev.mysql.com/show-profile.html
If LIMIT is given, OFFSET offset may be added to begin the output offset rows into the full set of rows. The Status values are like the State values displayed by SHOW PROCESSLIST, although there might be some minor differences in interpretion for ...