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Adapting DML Statements to memcachedOperations

Benchmarks suggest that the InnoDBmemcachedplugin speeds up DML operations (inserts, updates,

and deletes) morę than it speeds up queries. You might focus your initial development efforts on writeintensive

applications that are l/O-bound, and look for opportunities to use MySQL for new kinds of

write-intensive applications.

•INSERT INTO tl (key,val) VAUJES (some_key,some_value);

SELECT val FROM tl WHERE key = some_key;

UPDATE tl SET val - new_valueWHERE key - some_key;

UPDATE tl SET val = val + x WHERE key = some_key;

DELETE FROM tl WHERE key = some_key;

Single-row DML statements are the most straightforward kinds of statements to turn into memcached

operations: INSERT becomes add, UPDATE becomes set, incror decr, and DELETE becomes

delete. When issued through the memcachedinterface, these operations are guaranteed to affect

only 1 row because key is unique within the table.

In the preceding SQL examples, tl refers to the table currently being used by the

InnoDB

memcachedplugin based on the configuration settings in the

innodb_memcache.containers

table, key refers to the column listed under key_columns, and val refers to the

column listed

under value_columns.

• TRUNCATE TABLE tl;

DELETE FROM tl;

Corresponds to the flush_alloperation, when tl is configured as the table for

memcached

operations as in the previous step. Removes all the rows in the table.