Status Variables

InnoDB Buffer Pool

The InnoDB Buffer Pool is the memory area where the InnoDB Storage Engine caches its data and index blocks. Each InnoDB data and index block has a size of Innodb_page_size (16384 byte = 16 kbyte). The InnoDB Buffer Pool is configured in bytes with the innodb_buffer_pool_size variable. On a dedicated system the InnoDB Buffer Pool can be configured up to 80% of the systems physical RAM (free).

The innodb_buffer_pool_awe_mem_mb variable is relevant only on 32-bit Windows systems with more …

Because I do a lot of Performance Tuning gigs I get often in contact with these status variables. In the beginning I had a problem to understand them and now I have a problem to memorize the relation of the name and the meaning. Therefore I wrote this little summary:

Prepare the example

To show you the effect I have worked out a little example:

CREATE TABLE test (
    id    INT UNSIGNED NOT NULL AUTO_INCREMENT PRIMARY KEY
  , data  VARCHAR(32)
  , ts    TIMESTAMP
  , INDEX (data)
);

INSERT INTO test
VALUES …