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https://dev.mysql.com/mysql-shell-tutorial-javascript-documents-in-tables.html
values(null, "San Francisco", "USA", "California", '{"Population":830000}') Query OK, 1 item affected (0.01 sec) You can issue a query with a search condition that evaluates document values in the expression. In MySQL, a table may contain ...
https://dev.mysql.com/optimizing-innodb-bulk-data-loading.html
For optimal performance when loading data into an InnoDB FULLTEXT index, follow this set of steps: Define a column FTS_DOC_ID at table creation time, of type BIGINT UNSIGNED NOT NULL, with a unique index named FTS_DOC_ID_INDEX. For example: CREATE ... These performance tips supplement the general guidelines for fast inserts in Section 8.2.5.1, “Optimizing INSERT ...
https://dev.mysql.com/performance-schema-timing.html
If an enabled instrument is not timed, events produced by the instrument have NULL for the TIMER_START, TIMER_END, and TIMER_WAIT timer values. Events that have not yet completed have an END_EVENT_ID value of NULL. Events are collected by means of ...
https://dev.mysql.com/precision-math-expressions.html
By default, division by zero produces a result of NULL and no warning. sql_mode Value Result '' (Default) No warning, no error; i is set to NULL. With precision math, exact-value numbers are used as given whenever possible. For example, numbers in ...
https://dev.mysql.com/rename-table.html
row *************************** Table: t3 Create Table: CREATE TABLE `t3` ( `i1` int(11) DEFAULT NULL, `i2` int(11) DEFAULT NULL, CONSTRAINT `t3_chk_1` CHECK ((`i1` > 0)), CONSTRAINT `t3_chk_2` CHECK ((`i2` < 0)) ) ENGINE=InnoDB DEFAULT ... RENAME ...
https://dev.mysql.com/show-create-table.html
row *************************** Table: t Create Table: CREATE TABLE `t` ( `id` int(11) NOT NULL AUTO_INCREMENT, `s` char(60) DEFAULT NULL, PRIMARY KEY (`id`) ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 As of MySQL 8.0.16, MySQL implements CHECK ... SHOW ...
https://dev.mysql.com/show-engines.html
row *************************** Engine: BLACKHOLE Support: YES Comment: /dev/null storage engine (anything you write to it disappears) Transactions: NO XA: NO Savepoints: NO *************************** 3. row *************************** Engine: ...
https://dev.mysql.com/show-slave-status.html
In MySQL 8.0, this field is NULL (undefined or unknown) if the slave SQL thread is not running, or if the SQL thread has consumed all of the relay log and the slave I/O thread is not running. (In older versions of MySQL, this field was NULL if the ... SHOW SLAVE STATUS [FOR CHANNEL channel] This statement provides status information on essential parameters of the slave ...
https://dev.mysql.com/show-warnings.html
mysql> CREATE TABLE t1 (a TINYINT NOT NULL, b CHAR(4)); Query OK, 0 rows affected (0.05 sec) mysql> INSERT INTO t1 VALUES(10,'mysql'), (NULL,'test'), (300,'xyz'); Query OK, 3 rows affected, 3 warnings (0.00 sec) Records: 3 Duplicates: 0 Warnings: 3 ... SHOW WARNINGS [LIMIT [offset,] row_count] SHOW COUNT(*) WARNINGS SHOW WARNINGS is a diagnostic statement that displays information about the conditions (errors, warnings, and notes) resulting from executing a statement in the current ...
https://dev.mysql.com/spatial-operator-functions.html
Unless otherwise specified, functions in this section handle their arguments as follows: If any argument is NULL, the return value is NULL. ST_ConvexHull() handles its arguments as described in the introduction to this section, with this exception: ... OpenGIS proposes a number of functions that can produce ...
Document created the 26/06/2006, last modified the 26/10/2018
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