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https://dev.mysql.com/innodb-memcached-ddl.html
You can access the underlying InnoDB table (which is test.demo_test by default) through standard SQL interfaces. However, there are some restrictions: When querying a table that is also accessed through the memcached interface, remember that ...
https://dev.mysql.com/innodb-trx-table.html
TRX_REQUESTED_LOCK_ID The ID of the lock the transaction is currently waiting for, if TRX_STATE is LOCK WAIT; otherwise NULL. TRX_WAIT_STARTED The time when the transaction started waiting on the lock, if TRX_STATE is LOCK WAIT; otherwise NULL. The ...
https://dev.mysql.com/numeric-type-attributes.html
When you insert a value of NULL into an indexed AUTO_INCREMENT column, the column is set to the next sequence value. (AUTO_INCREMENT sequences begin with 1.) Storing 0 into an AUTO_INCREMENT column has the same effect as storing NULL, unless the ...
https://dev.mysql.com/spatial-convenience-functions.html
Unless otherwise specified, functions in this section handle their arguments as follows: If any argument is NULL, the return value is NULL. For example, this polygon is geometrically invalid: POLYGON((0 0, 0 0, 0 0, 0 0, 0 0)) ST_Validate() returns ... The functions in this section provide convenience operations on geometry ...
https://dev.mysql.com/spatial-relation-functions-object-shapes.html
Unless otherwise specified, functions in this section handle their arguments as follows: If any argument is NULL or any geometry argument is an empty geometry, the return value is NULL. ST_Crosses() handles its arguments as described in the ... The ...
https://dev.mysql.com/writing-protocol-trace-plugins.html
Function members for which the plugin needs no processing can be declared as NULL in the descriptor, in which case you need not write any corresponding function. trace_stop() is passed the connection handler and a pointer to the memory allocated by ... MySQL supports the use of protocol trace plugins: client-side plugins that implement tracing of communication between a client and the server that takes place using the client/server ...
https://dev.mysql.com/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/condition-pushdown-optimization.html
column IS [NOT] NULL column IN (value_list) Each item in the value_list must be a constant, literal value. This optimization improves the efficiency of direct comparisons between a nonindexed column and a constant. In such cases, the condition is ...
https://dev.mysql.com/create-table-generated-columns.html
Generated column definitions have this syntax: col_name data_type [GENERATED ALWAYS] AS (expr) [VIRTUAL | STORED] [NOT NULL | NULL] [UNIQUE [KEY]] [[PRIMARY] KEY] [COMMENT 'string'] AS (expr) indicates that the column is generated and defines the ...
https://dev.mysql.com/creating-spatial-indexes.html
For InnoDB and MyISAM tables, MySQL can create spatial indexes using syntax similar to that for creating regular indexes, but using the SPATIAL keyword. For storage engines that support nonspatial indexing of spatial columns, the engine creates a ...
Document created the 26/06/2006, last modified the 26/10/2018
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