PDF (US Ltr)
- 35.1Mb
PDF (A4)
- 35.2Mb
Man Pages (TGZ)
- 256.4Kb
Man Pages (Zip)
- 361.2Kb
Info (Gzip)
- 3.4Mb
Info (Zip)
- 3.4Mb
Search Results
https://dev.mysql.com/doc/refman/5.7/en/myisamchk-table-info.html
For strings, it may be shorter than the full length of the indexed column, because you can index a prefix of a string column. Nullpos, Nullbit For columns that can be NULL, MyISAM stores NULL values as a flag in a byte. Depending on how many ... To ...
https://dev.mysql.com/doc/refman/5.7/en/show-slave-status.html
In MySQL 5.7, this field is NULL (undefined or unknown) if the replica SQL thread is not running, or if the SQL thread has consumed all of the relay log and the replica I/O thread is not running. (In older versions of MySQL, this field was NULL if ... SHOW SLAVE STATUS [FOR CHANNEL channel] This statement provides status information on essential parameters of the replica ...
https://dev.mysql.com/doc/refman/5.7/en/change-master-to.html
Setting MASTER_HOST='' (that is, setting its value explicitly to an empty string) is not the same as not setting MASTER_HOST at all. Beginning with MySQL 5.5, trying to set MASTER_HOST to an empty string fails with an error. Previously, setting ...] ...
https://dev.mysql.com/doc/refman/5.7/en/outer-join-simplification.html
Instead, MySQL converts the query to a query with no outer join operation if the WHERE condition is null-rejected. (That is, it converts the outer join to an inner join.) A condition is said to be null-rejected for an outer join operation if it ...
https://dev.mysql.com/doc/refman/5.7/en/all-subqueries.html
The expression is FALSE if table t2 contains (12,6,NULL,-100) because there is a single value 12 in table t2 that is greater than 10. The expression is unknown (that is, NULL) if table t2 contains (0,NULL,1). The expression is TRUE if table t2 ...
https://dev.mysql.com/doc/refman/5.7/en/innodb-online-ddl-operations.html
When you add a primary key using the ALGORITHM=COPY clause, MySQL converts NULL values in the associated columns to default values: 0 for numbers, an empty string for character-based columns and BLOBs, and 0000-00-00 00:00:00 for DATETIME. Online ...
https://dev.mysql.com/doc/refman/5.7/en/aggregate-functions.html
GROUP_CONCAT(expr) This function returns a string result with the concatenated non-NULL values from a group. For information about a change in MySQL 8.0 that permits bit operations to take binary string type arguments (BINARY, VARBINARY, and the ...
https://dev.mysql.com/doc/refman/5.7/en/mysql-cluster-replication-conflict-resolution.html
The name of this table is that of the table for which conflict resolution is to be applied, with the string $EX appended. (An example that uses NDB$OLD() with an exceptions table is shown later in this section.) Additional columns may optionally be ... Requirements Source Column Control Conflict Resolution Control Conflict Resolution Functions Conflict Resolution Exceptions Table Conflict Detection Status Variables Examples When using a replication setup involving multiple sources (including circular replication), it is possible that different sources may try to update the same row on the replica with different ...
https://dev.mysql.com/doc/refman/5.7/en/gis-wkt-functions.html
LineFromText(wkt [, srid]), LineStringFromText(wkt [, srid]) ST_LineFromText(), ST_LineStringFromText(), LineFromText(), and LineStringFromText() are synonyms. LineFromText() and LineStringFromText() are deprecated; expect them to be removed in a ...
https://dev.mysql.com/doc/refman/5.7/en/information-functions.html
The result value is 0, or NULL for inappropriate arguments such as a NULL or negative repeat count. mysql> SELECT CHARSET('abc'); -> 'latin1' mysql> SELECT CHARSET(CONVERT('abc' USING utf8)); -> 'utf8' mysql> SELECT CHARSET(USER()); -> 'utf8' ...It ...